A cooling system of a data center computer room and a data center are provided. A specific embodiment of the system comprises: a liquid cooling system, including a liquid cooling cabinet, a heat exchanger forming a first circulation loop with the liquid cooling cabinet, and a cooling tower forming a second circulation loop with the heat exchanger; and a radiant cooling system, including a water pipe absorbing radiant heat in the data center computer room, a water chilling unit forming a third circulation loop with the water pipe, and a cooling tower forming a fourth circulation loop with the water chilling unit. The embodiment has improved the cooling efficiency of the data center computer room.