Abstract: The design scheme and critical technology of a 64 channel C-band high integration multi-functional motherboard are introduced in this paper. This integrated motherboard is applied to the front end simulation sub-array of active phased array radar. The power module, wave control module and chip T/ R component are integrated into the sub-array motherboard by using the multi-layer printed board pressing technology. Through the simulation design of each function network performance and electromagnetic compatibility design, finally the integrated motherboard design are completed. The dimensions of the 64 channel C-band mother-board are 228 mm×308 mm×4. 8 mm, the amplitude and phase consistency of the measured passive radio network channel is better than ±0. 1 dB, ±1°, and the amplitude and phase consistency of the active receiving link channel is better than ±1. 4 dB, ±5°. The integrated motherboard can realize the two-dimensional expansion of radar array size through block splicing. It is suitable for multiple layout schemes to avoid inefficient and repetitive design.