A quantum signature scheme is proposed for multiple people signature situation. The digest of the classical message of any length is obtained via Hash function and transformed into quantum bits in the sender. Each signatory uses his private key XOR the digest and gets a sequence. The quantum bits are performed a controlled unitary transformation according to the sequence by the signatory in turn, and signature information is state of the quantum bits. A trusted arbitrator is presented to verify the signature. The progress of verification uses idea of classical parity. Analysis shows that the length of the signature doesn’t get longer with the number of signatory increased in the scheme. The communication efficiency is high, and the progress of verification is simple.