Abstract: A silicon-based reconfigurable microwave photonic multi-beam forming network chip comprises an optical fiber coupler, an optical switch array, an optical divider, an ultra-wideband continuously adjustable optical true delay line array and a detector array; the optical fiber coupler is configured for inputting a single-sideband modulated optical signal of a microwave photonic phased array radar; the optical switch array and optical divider are configured for forming the reconstruction of the number of array elements used for a microwave photonic multi-beam and a microwave photonic single-beam; the ultra-wideband continuously adjustable optical true delay line array is configured for independently adjusting the delay on each microwave array element; and the detector array is configured for outputting a microwave signal. The chip provides large instantaneous bandwidth, high resolution, and reconfigurable microwave photonic multi-beam forming for the microwave photonic phased array radar.