Motivation： To recognize one's identity, we currently rely on gene detection to gain a precise verification. But it's too complicated to be applied in our real lives. Signature has been used widely in the fields of Finance and Security as a valid representative of personal identity. However, only through the writing, security is far from guaranteed.Now we have several methods for identity authentication, which show obvious flaws. Fingerprint identification is widely used for online checkout. But using plasticine or silica gel can easily copy others fingerprint. The online deals cannot guarantee secure transaction, on the contrary, increase its dealing risky objectively.Face recognition is also regarded as a possible alternative option, while it can be deceived just by using picture. Hence, we come out with this idea to recognize one's signature through the way they write. With a view to physiologic habit, which is not likely to be learned by others, we have a faith in its future development prospect.