An EVS readout circuit was developed using the XFAB 180 nm CMOS process. The circuit was designed for an event-based vision sensor, analyzing the asynchronous timing of row and column scanners and the impact of event output data volume on circuit performance. Asynchronous timing is implemented 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 the output of redundant event information and increasing the event readout rate. Each pixel integrates a logarithmic light sensing circuit, a switch-capacitor amplifier circuit, and a two-transistor comparator to generate event information, with a power consumption of 54.3 nW per pixel. The readout circuit operates at 1.8 V, with a maximum event rate of 41 Meps. In a 64×64 array, the total power consumption of the circuit at an event rate of 1 Meps is 15.31 mW, and the data output switching process is capable of reducing redundant event output by up to 50%.