BACKGROUND: Disclosure of HIV serostatus is important for the prevention of HIV infection among men who have sex with men (MSM). However, knowledge of sexual partners' HIV status among MSM in China is low. As a complement to HIV testing services, HIV self-testing (HIVST) has considerable potential to promote serostatus disclosure. OBJECTIVE: The primary objective of our trial is to evaluate the effect of HIVST on improving serostatus disclosure to sexual partners. We hypothesize that MSM in an intervention condition will have a higher awareness of the HIV status of their sexual partners compared with MSM in the control condition. The secondary aims are to evaluate (i) changes in sexual behaviors after disclosure of HIV status by sexual partners, (ii) promotion of the frequency of HIV and syphilis testing on participants and their sexual partners, and (iii) factors that restrict the disclosure of HIV infection to sexual partners. We hypothesize that MSM in the intervention condition will exhibit safer sexual decision making and a higher rate of HIV testing uptake compared with MSM in the control condition. METHODS: A stepped wedge randomized controlled trial will be conducted throughout China. Study recruitment of 800 MSM will be promoted through advertisements released on WeChat public accounts. Individuals who are born biologically male, aged ≥18 years, HIV negative, and who have not undergone HIV testing in the past 3 months will be recruited. Eligible men will be randomly divided (1:1:1:1) into four groups and randomized. The group cluster will initiate the intervention so that participants will be provided with 2-4 free finger prick-based HIVST kits until trial completion. The intervention period for participants in each of the four groups will be initiated at 3-month intervals. Men in both groups will be required to complete a baseline and four follow-up surveys every 3 months. The primary intervention outcome will evaluate the effect of the distribution of HIVST kits on improvement in the disclosure of sexual partners' HIV status. The secondary outcomes will be changes in sexual behaviors after disclosure of HIV status from sexual partners, the promotion of the frequency of HIVST on participants and their sexual partners, and the factors that restrict disclosure of HIV status to sexual partners. RESULTS: Subject recruitment began in August 2018. The first round of follow-up surveys post intervention is complete, with three rounds remaining to be done. Data analysis was scheduled for April 2020 and the results will be disseminated through conferences and peer-reviewed publications. CONCLUSIONS: Few studies have evaluated interventions to increase knowledge of sexual partners' HIV status among MSM. Our trial will provide information on the link between HIVST and HIV serostatus disclosure. The findings of this trial will facilitate the implementation of HIVST services to help control the spread of HIV among MSM in China. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1800019453; http://www.chictr.org.cn/showproj.aspx?proj=30158. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/17788.