Abstract: In order to solve the temperature non-uniformity on phased array antenna, three topology structures are designed, including:microchannel based on S type, horizontal micro-channel based on similar tree bifurcation, and longitudinal microchannel based on T type. Numerical simulation is carried on to study the temperature uniformity of three microchannel heat sinks with multiple sources. The results show that longitudinal microchannel based on T type has the best uniformity of temperature which is verified by the experiment, and the temperature uniformity is reduced as the total power goes up, yet improved with the increase of inlet flow rate. The study provides a useful reference for the thermal design of phased array antenna with multiple sources.