The objective function of phase time allocation based on vehicle demand was proposed, and the basic model for phase time allocation of intersections with pedestrian crossing constraints was established, considering the traffic demands of non-critical movement, overlap phase movement, interrupted phase movement and pedestrian. The optimization model of phase design scheme was established, aiming at the optimization problem of multiple optional signal phase design schemes and combined with the basic model for phase time allocation of intersections. The proposed model can realize the synchronous optimization of intersection phase design and signal timing. A multi-round phase time allocation model was presented, for the phase time allocation of multiple overlap phase movement, interrupted phase movement and non-critical movement. The phase time allocation process was given and a simultaneous optimization method of signal phase design and timing at intersection was proposed based on the proposed allocation model. Case analysis shows that the model can optimize signal phase structure and allocate phase time in multiple rounds. It can deal with the complex phase design conditions such as overlap phase, interrupted phase and repeated phase, and take into account the demand of pedestrian crossing, so as to better ensure the overall operation efficiency of intersections.