This is a dose escalation trial. The dosing regimen involves a single-dose study. This is a single-center, randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetic characteristics of TQC3927 powder for inhalation in healthy adults subjects.

Inclusion Criteria:

• Subjects voluntarily joined the study, sign informed consent form before the study and fully understand the study content;
• Healthy subjects aged between 18 and 45 years (inclusive), both male and female;
• The male subject should weigh at least 50kg, the female subject should weigh at least 45kg. And body mass index (BMI) within 19~28 kg/m2;
• Have no pregnancy plan and voluntarily take effective contraception measures from time of screening to at least 90 days after the last dose (subjects and their partners).

Exclusion Criteria:

• Participated in any clinical trial within 3 months prior to the screening period;
• Past medical history or current cardiac, breath，endocrine, metabolic, renal, hepatic, gastrointestinal, skin, infection, hematological, neurological or psychiatric diseases/abnormalities, or related chronic abnormalities, or related chronic diseases, or acute diseases, and the investigator evaluated that the subject was not suitable for the trial;
• Individuals with a history of glaucoma, functional constipation, benign prostatic hyperplasia, urinary tract obstruction, etc;
• People who have received or are planning to receive inactive or active vaccines during the 30 days prior to the screening period and the entire study period；
• Current history of active tuberculosis, bronchiectasis or other non-specific lung diseases；
• Any history of drug allergies, Individuals with a specific history of allergies or allergies；
• Smoking more than 5 cigarettes per day or using equivalent amounts of nicotine or nicotine-containing products during the 3 months Before first administration, or those who cannot stop using any tobacco-based products during the trial；
• Regular alcohol consumption within the first 6 months of screening (women drink more than 14 standard units per week and men drink more than 21 standard units per week (1 unit = 360 mL of beer or 45 mL of 40% alcohol or 150 mL of wine) of alcohol per week during the 3 months prior to screening, or those who cannot refrain from alcohol during the trial, or those who tested positive for alcohol breath；
• History of drug or narcotics abuse or a positive result of urine drug test at screening；
• People who have abnormal and clinically significant results in vital signs, physical examination, laboratory tests, chest radiograph and abdominal ultrasound during screening period；
• Those who have special dietary requirements and cannot follow a unified diet；
• Subjects Positive for Any of Hepatitis B Virus Surface Antigen (HBsAg), Hepatitis C Virus Antibody (Anti-HCV), Human Immunodeficiency Virus Antibody (Anti-HIV), and Treponema Pallidum Antibody (Anti-TP)；
• Pregnant or lactating women or those with positive blood pregnancy test results during the screening period；
• Subjects who are still unable to use TQC3927 inhalation powder correctly after training；
• Any situation in which the investigator believes that this poses a safety risk to the subject in the trial or may interfere with the conduct of the study, or that the investigator believes that the subject may not be able to complete the study or may not be able to comply with the requirements of the study.