The invention relates to the technical field of bearing detection, in particular to a bearing fault detection clamp, a detection system and a using method thereof. The bearing fault detection clamp comprises a clamping substrate, an acceleration sensor and bearing clamping piece sets, the clamping substrate is provided with the acceleration sensor and the bearing clamping piece sets, the upper andlower bearing clamping piece sets fix a to-be-tested bearing in the vertical direction, each bearing clamping piece set comprises two bearing clamping pieces, the two bearing clamping pieces clamp the to-be-tested bearing and fix the to-be-tested bearing in the horizontal direction, each bearing clamping piece set clamps the outer race of the to-be-tested bearing through a locking nut, bearings of different thicknesses can be conveniently clamped; a bearing positioning block is arranged between the upper and lower bearing clamping piece sets, one end of the positioning block is connected withthe clamping substrate, an arc positioning plate is arranged at the other end of the positioning block, and the arc positioning plate is attached to the outer race of the to-be-tested bearing. Pressure is evenly transmitted to the bearing conveniently, and the testing precision is improved.