The invention provides a space mechanical arm suspension microgravity simulation method, and belongs to the field of simulation experiments, wherein the method comprises the steps: S1, installing a space machine, and controlling a six-degree-of-freedom table to move to a test starting position on an air floatation platform; S2, adjusting the alignment position according to the target point of thesix-degree-of-freedom table; S3, controlling a mechanical swing arm to move, and connecting a suspension assembly with a suspension point; S4, controlling an omnidirectional mobile platform to move along with the six-degree-of-freedom platform; S5, controlling a space mechanical arm to be unfolded; S6, after the space mechanical arm completes the test, controlling the space mechanical arm to moveto an original folded state; S7, after the six-degree-of-freedom table moves to the parking position, closing an air source, and supporting and fixing the six-degree-of-freedom table; and S8, ending the test of disassembling a suspension assembly. The action of the gravity of the mechanical arm on the posture of a spacecraft when the mechanical arm is unfolded is eliminated, meanwhile, more motionfreedom degrees and motion ranges of the mechanical arm are reserved, and the unfolding range of the space mechanical arm is adapted to in a large range.