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.