The multimodal biometrics payment is a new technology that allows people to pay with their own biometrics such as fingerprints, face, hands and so on. In this paper, the biometrics verification techniques combining with digital signature for multimodal biometrics payment system are introduced. Considering the high universality, distinctiveness, easy collect ability of fingerprint and face, a multimodal biometrics verification system with fingerprint and face as inputs is designed, and the hybrid fingerprint features and infrared (IR) face features for matching is to overcome the shortcomings of the traditional methods and grantee the integrity of the registered multimodal biometrics data. And then nine authentication models for authenticating an open network to ensure the integrity of these data are analyzed respectively. At last, a digital signature procedure with the Public Key Infrastructure (PKI) to illustrate a multimodal biometrics payment system with safe model is proposed. The proposed system can be applied to some public key platforms, too.