The difference in structure between virtual desktop system and traditional PC desktop system causes “semantic differences” and efficiency issues, when improving the trust level of the security mechanisms of virtual desktop system.A security virtual machine integrity monitor (SVMIM) was build based on network bootstrap mechanism. SVMIM adopted a hybrid security structure, monitored and controlled the loading process of executable files in virtual desktop systems, which could effectively overcome the shortcomings of “semantic gap” and ensure the trustworthiness of security mechanism. In addition, SVMIM used storage clone technology on network storage to reduce the impact of security mechanism to the system performance. The performance testing on SVMIM prototype and the performance analysis showed its flexibility and advantage.