Aim To keep away the new type of Trojan horse based on SPI.Methods Analyze the hiding mechanism of new Trojan proceeding from the principle of SPI technique and excogitate a method to check and clean this type of Trojan accordingly.Results A whole defending scheme was put forward for this new type Trojan horse and the implementation was described in detail.Conclusion At present,all kinds of existing anti-Virus applications can do nothing to the new type of Trojan horse based on SPI.A feasible periodic comparison method was provided to actualize automatic-manual cleaning of the new type Trojan horse.