The invention relates to an independent adaptor piece used for a plastic scintillator detector array environment test. The independent adaptor piece comprises an I-beam force transmission structure, the two opposite sides of the I-beam force transmission structure are respectively provided with an upper planar portion and a lower planar portion, the width of the upper planar portion is smaller than the width of the lower planar portion, four upper installation holes are arranged at four corners of a rectangular of the upper planar portion, the lower planar portion is symmetrically provided with two columns of lower installation holes, and each column is uniformly provided with three. According to the invention, the independent adaptor piece structurally utilizes an I-beam force transmission performance feature and realizes large rigidity and good mechanical vibration spectrum transmission performance. Four connection holes in the upper surfaces of adaptor pieces are connected with a plastic scintillator detector array, six connection holes in the lower surfaces are connected with a vibration table expansion bench or a shock testing machine expansion bench, through open design at two sides, the operation space is sufficient, the application is facilitated, the installation moment requirement of a product is satisfied, and the environment test can also be conveniently mounted and dismounted.