The security issue of MA(mobile agent) is concerned for a long time, Especially for attack from malicious hosts. The paper proposes a new security routing protocol whose highlight is integrating group signature into MA system. It will decrease the probability that malicious hosts cluster to skip one host deliberately, and avoid too much invalid connection to host who is offline or rejective to service. Besides, in new protocol, each host will hold less public keys of other hosts and save time on verifying MA. The last superiority of new protocol is improving the efficiency of DoS(denial of service) attacker tracing