This paper constructs the relationship theory model of multi-dimension trust, knowledge transfer and software outsourcing performance. Based on a theoretical analysis and an investigation into 97 software outsourcing enterprises in Jingjinji Region via a questionnaire and an empirical study, it is found that: firstly, multi-dimensional trust has different impact on the knowledge transfer and outsourcing performance. Secondly, explicit knowledge transfer has more significant influence on software outsourcing performance compared with tacit knowledge transfer. Thirdly, knowledge transfer has different mediating effects on various dimensional trust and outsourcing performance, in which knowledge transfer has completely mediating effect between ability-based trust and outsourcing performance and has partial mediating effect between calculus-based trust and outsourcing performance as well as kindness-based trust and outsourcing performance.