The invention discloses a CMOS image sensor, a timing control method and an exposure method thereof. The image sensor includes a pixel array composed of multiple pixel rows and a control chip controlling the array. The control chip controls each pixel row to expose in the exposure time during one exposure period of the pixel row, and then wait predetermined time after the exposure time to output data. In the invention, the exposure time of the image sensor is separated from the time of outputting data. Therefore, the working mode of the image sensor can be controlled more flexibly. By the manner of controlling the pixel rows in the sub-array of the image sensor to expose synchronously, the flash time of the light source is the same as the exposure time of each single sub-array, thereby improving the utilization efficiency of the source energy and ensuring real-time image sampling.