An EVS readout circuit was designed based on the XFAB 180nm CMOS process. The circuit is designed for an event-based vision sensor, analyzing the asynchronous timing of row and column scanner and the impact of event output data volume on the circuit. The readout circuit implements asynchronous timing through row and column scanning, improving time resolution and reducing the power consumption and delay of the readout circuit. The circuit automatically switches data output methods based on row event density, reducing redundant event information output and increasing event readout rate. The pixel part includes a logarithmic light sensing circuit, a switch-capacitor amplifier circuit, and a two-transistor comparator to output event information, with a single pixel power consumption of 54.3nW. The readout circuit operates at 1.8V, with a maximum event rate of 41MEps. In a 64×64 array, the total power consumption of the circuit at 1MEps event rate is 15.31mW, and the method of switching data output can reduce the output of redundant event information by up to 50%.