This is a multiple-center, randomized, double-blind, placebo-controlled study design evaluating the safety, efficacy, and pharmacokinetics (PK) parameter of HL-1186 tablet for moderate to severe acute pain after surgery.

Inclusion Criteria:

1. 18 years old ≤ age ≤ 75 years old, gender is not limited.
2. 18 kg/m2 ≤ Body Mass Index (BMI) ≤ 30kg/m2.
3. Scheduled to undergo one of the following elective surgeries under general anesthesia: Orthopedic surgery, abdominal surgery, or thoracic surgery.
4. Able to understand the research process and the use of pain scales, and communicate effectively with researchers.
5. Participant reported pain of ≥4 on the NRS.

Exclusion Criteria:

1. Prior history of surgery at the same site, and this may affect pain perception at the surgical site per investigator's judgments.
2. Allergy to any component of the investigational product, to perioperative anesthetic/analgesic/antiemetic agents, or to ≥3 substance allergies.
3. Use of the prohibited medications specified in the protocol within 5 half-lives of the drug (or 7 days if half-life is unknown) prior to randomization, and this may affect pain or scale assessments per investigator's judgments.
4. QTcF ≥450 ms (using Fridericia correction), unstable angina, myocardial infarction, severe arrhythmias (e.g., third-degree atrioventricular block), New York Heart Association (NYHA) class III or higher cardiac function, recurrent asthma, etc., within screen period, and deemed ineligible per investigator's judgments.
5. High bleeding risk conditions: Congenital bleeding disorders (e.g., hemophilia), platelet function abnormalities (e.g., idiopathic thrombocytopenic purpura, disseminated intravascular coagulation, congenital platelet function abnormalities), active bleeding, etc., and deemed ineligible per investigator's judgments.
6. For female participants: Pregnant or lactating (within 1 year postpartum).
7. Participants with childbearing potential planning conception/sperm/egg donation within 6 months post-treatment, or unwilling to use effective contraception (abstinence, barrier methods, oral contraceptives, intrauterine device, or sterilization).
8. Participants who have participated in other investigational product/device studies within 30 days prior to the screening visit, or are currently enrolled in another study.
9. Judgment by the investigator that the participant should not enter the study due to other conditions.