Security of computer architecture is basis of trusted system. For the sake of compromising to commerce,trusted computing platform’s product is really not the best secure architecture. It is short of supporting trust spread because of chain trust relationship. So we put forward a specific trust model, and then advance a secure and reconfigurable architecture distinguishing from traditional architectures. The model can give prominence to trusted root and reduce the loss of trust after trust chain had transferred. We also design out new architecture according to our model. The prototype system validates that new architecture can effectively resolve trust expansion.