The invention belongs to the field of crisp and hard material ultra-precision machining, and provides an efficient mechanical polishing method for yttrium aluminum garnet crystals. The efficient mechanical polishing method for yttrium aluminum garnet crystals comprises the following steps that (1) under the room temperature, zirconium oxide as an abrasive material, sodium hydroxide as a chemical reagent, and additives are added into deionized water and subjected to ultrasonic oscillation to be prepared into chemical mechanical polishing liquid; (2) an IC1000 polishing pad serves as a polishingpad for chemical mechanical polishing, and is trimmed; and (3) process parameters are selected, and yttrium aluminum garnet crystal plates are subjected to chemical mechanical polishing. By means ofthe efficient mechanical polishing method for yttrium aluminum garnet crystals, the yttrium aluminum garnet crystal plates with low damage are obtained with a higher material removal rate.