Developing highly efficient catalysts for photocatalytic hydrogen generation from water splitting is one of the grand challenges in solar energy conversion. Herein, we report the design and synthesis of a library of donor-pi-acceptor (D-pi-A) conjugated microporous polymer (CMP) photocatalysts using pyrene, benzothiadiazole, and benzene (biphenyl) as donor, acceptor, and pi crosslinker units, respectively. By adjusting the ratio of pyrene to benzothiadiazole units, a range of CMPs with various polymeric structures and components was synthesized and the influence of the molecular structures on the photocatalytic performance was comparatively investigated. Photocatalytic hydrogen evolution rate (HER) up to 106 mu mol h(-1) was achieved on PyBT-2 with a ratio of 9:2 of pyrene to benzothiadiazole under UV-vis light irradiation (lambda > 300 nm). The structure-performance relationships revealed in this work offer a fundamental understanding in the rational design of CMPs for high performance organic photocatalysts.