The invention discloses a test reaction device. The device is used for carrying out microbial grouting to reinforce a sandy soil body under organic matrix regulation and control. A support device usedfor placing the sandy soil body is arranged in a reaction container. A top end of the reaction container is provided with a solution grouting port and a bacteria liquid grouting port. A channel is arranged in the reaction container. A top of the channel is connected to the solution grouting port and the bacteria liquid grouting port, and a bottom is located above the sandy soil body. The reactioncontainer is provided with a sampling port and an exhaust port connected to the channel. A grouting uniformity device is arranged in the reaction container. A storage container is connected to the solution grouting port through a connection pipeline. The connection pipeline is provided with a first pump body. A bottom end of the reaction container is provided with a drainage port. The drainage port is provided with a first water stop valve. Two ends of a by-pass pipeline are connected to the two ends of the reaction container. The connection portion of the by-pass pipeline and the bottom endof the reaction container is provided with a second water stop valve. Sampling nondestructive performance, sample uniformity and water waterproofness of the device can be increased. The invention alsodiscloses a test reaction method.