The invention provides a rapid compensation-free three-point positioning clamp applied to a four-wheel aligner. The compensation-free three-point positioning clamp comprises a target frame assembly and a clamping head assembly. The target frame assembly comprises a rotary frame, three tire attaching bars and a target support. The three tire attaching bars are in the same plane and are fixed to the circumference of the rotary frame through connecting rods, the central axes of the connecting rods are distributed with a 120-degree angle and intersect at the center point of a rotary shaft, and the target support is fixed to the rotary frame and provided with an axial hole perpendicular to the tire attaching bars, and a target shaft locking device. The clamping head assembly comprises a rotary shaft connecting base, clamping heads and magnets, wherein the rotary shaft connecting base is connected with the target frame assembly through the rotary shaft in a rotatable mode, the clamping heads are fixed to a sliding groove, a left screw rod and a right screw rod, and the magnets are connected with the clamping heads. The compensation-free three-point positioning clamp is positioned by a clamping head sleeve, magnetic force of the clamping heads and the magnets generates tire attaching force to enable the three tire attaching bars to be tightly attached to tire faces, real parameters of tires on the ground can be accurately measured, and the compensation-free three-point positioning clamp has the advantages of being free of compensation, light in weight, high in universality, easy and fast to assemble and disassemble, high in reliability and the like.