The invention discloses a suspended horizontal three-point bending test system for testing type I fracture of materials. The test system comprises an operating platform, wherein a suspension system isarranged on the operating platform and comprises a constant magnetic plate and a suspension device; the suspension device comprises a clamping plate base, an electromagnetic controller, an electromagnetic device and two sample clamping plates; a movable groove is formed in a plane on one side of the clamping plate base; the two sample clamping plates are arranged in the movable groove; the electromagnetic controller and the electromagnetic device are arranged at the bottom of the clamping plate base; and a clamping extensometer, a loading end, a tension-compression sensor, a data analysis system, a servo loading system, a signal acquisition device, an acoustic emission sensor and a fixing piece are arranged on the operating platform. The invention further discloses a test method for the system. According to measurement of the samples in a balanced suspension state, friction force between the bottom of the samples and the contact surface of the cushion due to the self-supporting effectof the samples can be eliminated. Therefore, the test system is capable of more reasonably and accurately obtaining the type I fracture characteristics of the materials.