Abstract: According to the fact that there are some secure faults in software download schemes due to the lack of trust measurement in software download for mobile equipments,making use of trust mechanism of identity management and secure characteristics such as integrity verification,protect storage,domain isolation,access control and remote platform verifying trusted computing possess,software download service model based on trust measurement of trusted identity management architecture has been put forward,software download service process has been designed,software download service protocol has been studied,the security performance of the protocol has been analyzed,the security performance comparison between several software download schemes has been made,the result shows that the scheme improve security performance of software download effectively.