The invention provides a microwave power amplifier for improving temperature uniformity of a power unit. The microwave power amplifier for improving temperature uniformity of the power unit comprisesa plurality of power units which are arranged in parallel, wherein each power unit comprises a plurality of transistors, collectors of the transistors in two adjacent power units are electrically connected via a first connection unit, the first connection unit comprises a first metal layer, an insulation dielectric layer and a second metal layer which are sequentially arranged from bottom to top,the first metal layer of the first connection unit communicates with a cooling device, and the second metal layer of the first connection unit is connected with the collectors of the transistors in the two adjacent power units; and in the first connection unit, the area of the second metal layer is gradually reduced along a temperature reduction direction according to a temperature distribution direction of the transistors in the power units.