In order to overcome the traffic congestion due to the traffic demand for urban expressways that exceeds the traffic supply, the benefit of priority entrance is analyzed by fully considering the requirements of vehicles for priority entrance on the on-ramp of urban expressways, and an on-ramp control strategy based on the priority en- trance is proposed, which permits vehicles with top priority to drive into urban expressways in a peak traffic condi- tion. Moreover, an algorithm of priority entrance for the annular road sections of urban expressways is presented, and the corresponding numerical example is conducted. The results indicate that the proposed strategy is applicable to on-ramp control and helps to raise the use efficiency of roads because it can prevent vehicles with lower priority from entering urban expressways.