The invention discloses a long and short fiber composite strengthening thermoplastic plastic particle material and a production method thereof. The particle materials are composed of thermoplastic plastic substrate, strengthening long fibers and strengthening short fibers, wherein the strengthening long fibers have the same lengths as those of the particle materials, are parallelly distributed in the direction of particle material axis, and the short strengthening fibers are randomly and astatically distributed in the particle materials. Two strengthening fibers exist in the particle materials at the same time, namely the strengthening long fibers with the same lengths as those of the particle materials and the strengthening short fibers, which are randomly distributed in the particle materials, with different lengths. Therefore the particle materials integrate the strong mechanical property of the long fiber particle material LFT and the good processing technology property of the short fiber particle material SFT together. Furthermore, the ratio of the long fiber to short fiber in the particle materials can be adjusted through the technology to produce products with different mechanical properties and processing technology properties.