The goal of this prospective multicenter clinical trial is to evaluate the efficacy and safety of software-delivered cognitive behavioral therapy for insomnia (CBT-I) in Chinese patients with insomnia disorder (ID). The main questions it aims to answer are: (1) whether the software-delivered CBT-I is more effective than an online patient education (online-PE) at improving insomnia. (2) whether the software-delivered CBT-I is safe for treatment of insomnia symptoms.

Participants will be randomized to receive (1) a software-delivered CBT-I using automated software called 'resleep' (one kind of digital device expected to treat insomnia targeted for Chinese patients); (2) online patient education (online-PE) about sleep.

Researchers will compare the efficacy of a software-delivered CBT-I program and an online sleep education control at improving insomnia symptoms and other psychological outcomes.

Inclusion Criteria:

• Aged ≥18 years old, no gender limitation;
• Own a mobile-phone, access the Internet, and be skilled in using software;
• Meet the diagnostic criteria of insomnia disorder in the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5);
• Insomnia symptoms appear at least 3 nights per week and last for at least 3 months;
• ISI scores ≥ 12 ;
• Volunteer to participate in this experiment and sign a written informed consent.

Exclusion Criteria:

• Generalized Anxiety Disorder Scale-7 (GAD-7) scores ≥ 15;
• Patients Health Questionnaire-9 (PHQ-9) scores ≥ 20;
• Current thoughts of suicide or self-injury (defined as PHQ-9 9th item score ≥ 1);
• Confirmed physical diseases that may affect sleep, such as congestive heart failure, chronic obstructive pulmonary disease acute phase, cardiovascular and cerebrovascular disease acute phase, etc.
• Current diagnosed neurological or mental illness (major depressive disorder, bipolar disorder, epilepsy, schizophrenia, etc.) that may affect sleep;
• Diagnoses of other untreated sleep disorders, such as obstructive sleep apnea, restless leg syndrome (RLS);
• Usual bedtime (when the subject attempts to fall asleep) is earlier than 8 p.m. or later than 2 a.m., or usual waking (arising) time is earlier than 4 a.m. or later than 10 a.m.
• Alcohol or drug abusers (other than nicotine dependence) in the past year;
• Pregnant or lactating women;
• Undergoing systematic psychotherapy within the past 3 months;
• Undergoing other cognitive behavioral therapy for sleep disorders;
• Unstable usage of medication regimens that affect sleep (changes in type, dosage and method of use within the past 1 month);
• Night shift workers, travelers across time zones;
• Subjects who have not responded to previous CBT-I;
• Other conditions deemed unsuitable for clinical trials by the investigator.