The invention discloses a modular LED integrating sphere uniform light source. A mounting frame is arranged on a hemispherical face of an integrating sphere. Each mounting plate comprises a mounting block and an arc mounting strip. One end of each mounting block is connected with the bottom of the corresponding arc mounting strip. Multiple LED mounting holes are formed in each arc mounting strip.Screw holes are formed in the top ends of the mounting blocks and the top ends of the arc mounting strips. A fixed plate is arranged to be of a round structure and is uniformly provided with multiplescrew holes. LED lamps are fixed to the LED mounting holes in a gluing manner. According to the modular LED integrating sphere uniform light source, the mounting plates are connected with the integrating sphere, the holes are formed in the mounting plates to mount the LED lamps, and therefore the function of the uniform light source is achieved; and the good-quality and low-price uniform light source is used for optical detecting, scientific research, teaching and other purposes. By means of modular design, the problems that an existing uniform light source is inconvenient to maintain, singlein function, narrow in adjusting range and the like can be solved.