〔Abstract〕 Objective To analyze the current situation, influencing factors and mechanism of knowledge-attitude-practice(KAP) regarding acquired immune deficiency syndrome(AIDS)/sexually transmitted diseases(STDs) among migrant workers in Chengdu's main urban area, so as to provide a basis for the development of effective prevention and control policies for this group. Methods Convenience sampling and systematic sampling were used to collect demographic information and data on knowledge, attitudes, and sexual behavior characteristics of AIDS/STDs of the participants. The collected data were organized and statistically analyzed by EpiData 3.1 and SPSS 26.0 software. Additionally, a KAP path analysis model was constructed by using AMOS 24.0 software. Results A total of 257 valid questionnaires were obtained. The AIDS awareness rate was 55.6%, with a mean scores of(5.59±1.61). The awareness rate of STDs was 37.4%, with a mean scores of(9.05±3.00). Discrimination attitudes towards AIDS and STDs were reported by 58 participants(22.6%) and 44 participants(17.1%) respectively. The prevalence of high-risk sexual behavior was 3.50%. Men(OR=0.500, 95%CI: 0.279-0.897) acted as deterrents to knowledge of AIDS. On the other hand, childlessness facilitated discrimination against AIDS(OR=2.748, 95%CI: 1.385-5.451) and STDs(OR=2.287, 95%CI: 1.084-4.825). There was lower likelihood of engaging in high-risk sexual behavior among migrant workers in Chengdu's main urban area who were older(OR=0.854, 95%CI: 0.785-0.929). The occurrence of high-risk sexual behaviors was influenced both directly and indirectly by attitudes towards AIDS and related knowledge. There was a positive correlation between knowledge about AIDS and STDs and attitudes towards them(r=0.15,0.24, bothP<0.05), as well as between attitudes towards AIDS and attitudes towards STDs(r=0.57,P<0.05). That is, the higher the scores of knowledge, the less likely one was to hold discrimination attitudes. Therefore, increasing the rate of knowledge awareness could reduce discrimination towards AIDS/STDs and the occurrence of high-risk sexual behaviors. Conclusion The level of AIDS/STDs knowledge among the migrant workers in Chengdu′s main urban area is concerning. Innovative interventions should be intensified in key areas and populations.