We will introduce the construction and design of a new simultaneous three-channel multicolor CCD photometer. This photometer has been mounted on the 1.2-m telescope at Jilin Observatory, applying to study space debris, gamma-ray burst afterglows, asteroids and other rapidly variable objects. As one of the ground follow-up telescopes of the Chinese-French SVOM (Space-based multi-band astronomical Variable Objects Monitor) mission, it appears very essential to evaluate the performance of the photometry system of this photometer, which can achieve simultaneous imaging within field of view of 21.5'×21.5', 21.5'×21.5' and 21.3'×21.3' in the Sloan Digital Sky Survey (SDSS) g', r', i' bands, respectively. Photometric calibrations were carried out by using plenty of SDSS standard stars, the relationship between the photometric system and the Johnson-Bessel filter system was also studied. The results of the performance evaluation were then presented by observing open cluster M67.