A multistatic radar system can effectively improve the detection performance owing to its spatial diversity property. However, the detection performance will degrade when there exist multipaths. Time reversal has been proved to be able to transform the impact of the multipath into a favorable factor by matching propagation channels to achieve space-time focusing in a monostatic radar system. Therefore, we study the time reversal detection problem in a multistatic radar system with multipath environment in this paper. We divide the detection problems into two scenarios according to whether the channel response is known or not. In both scenarios, the time reversal detector and the conventional detector are derived respectively. Monte-Carlo experiments are used to examine the performance of the four detectors. The simulation results demonstrate that the time reversal detectors have a significant performance enhancement over the conventional detectors for the multistatic radar in a multipath environment, and more multipaths lead to better detection performance for the time reversal detectors. In addition, we also show that the detection probability improves with the increase of the number of radar transceivers.