A preparation method of an acellular allogeneic dermal matrix, characterized in that, the method comprises the following steps: Step 1), an allogeneic skin material is put into a solution of an enzyme(s), soaked and subjected to shaking treatment to obtain a semi-finished product A, wherein the enzymes are phospholipase and protease; the phospholipase is one or more of phospholipase A1, phospholipase A2, phospholipase C, and phospholipase D; AND the protease includes one or more of trypsin, bromelain, papain, and dispase; the solution of an enzyme(s) has a pH of 7.0 to 8.0; the concentration of the phospholipase is 0.1 g/L to 0.4 g/L; the concentration of the protease is 0.1 g/L to 0.3 g/L Step 2), the semi-finished product A is taken out, soaked with physiological saline, and subjected to shaking treatment to obtain a semi-finished product B; Step 3), the semi-finished product B is put into a surfactant solution, and subjected to ultrasonic soaking treatment to obtain a semi-finished product C; wherein the surfactant solution contains 0.1 to 0.3 g/L of SDS, which is sodium dodecyl sulfate, or the surfactant solution contains 0.1 to 0.3 g/L of Triton X-100, which is polyethylene glycol octyl phenyl ether. Step 4), the semi-finished product C is soaked with physiological saline, and subjected to shaking treatment to obtain a semi-finished product D; Step 5), the semi-finished product D is put into a container containing a DNA hydrolase solution, and subjected to shaking treatment to obtain a semi-finished product E; Step 6), the semi-finished product E is soaked with physiological saline, and subjected to shaking treatment to obtain a semi-finished product F; Step 7): the semi-finished product F is washed and soaked with water for injection to obtain a finished product G, or the method further comprises the following steps: Step 8): the finished product G is taken out, packaged, and sterilized to obtain a finished product H; or the finished product G is taken out, placed in a solution containing a lyoprotectant for freeze-drying, packaged, and sterilized to obtain a finished product H. Step 1), an allogeneic skin material is put into a solution of an enzyme(s), soaked and subjected to shaking treatment to obtain a semi-finished product A, wherein the enzymes are phospholipase and protease; the phospholipase is one or more of phospholipase A1, phospholipase A2, phospholipase C, and phospholipase D; AND the protease includes one or more of trypsin, bromelain, papain, and dispase; the solution of an enzyme(s) has a pH of 7.0 to 8.0; the concentration of the phospholipase is 0.1 g/L to 0.4 g/L; the concentration of the protease is 0.1 g/L to 0.3 g/L the solution of an enzyme(s) has a pH of 7.0 to 8.0; the concentration of the phospholipase is 0.1 g/L to 0.4 g/L; the concentration of the protease is 0.1 g/L to 0.3 g/L Step 2), the semi-finished product A is taken out, soaked with physiological saline, and subjected to shaking treatment to obtain a semi-finished product B; Step 3), the semi-finished product B is put into a surfactant solution, and subjected to ultrasonic soaking treatment to obtain a semi-finished product C; wherein the surfactant solution contains 0.1 to 0.3 g/L of SDS, which is sodium dodecyl sulfate, or the surfactant solution contains 0.1 to 0.3 g/L of Triton X-100, which is polyethylene glycol octyl phenyl ether. Step 4), the semi-finished product C is soaked with physiological saline, and subjected to shaking treatment to obtain a semi-finished product D; Step 5), the semi-finished product D is put into a container containing a DNA hydrolase solution, and subjected to shaking treatment to obtain a semi-finished product E; Step 6), the semi-finished product E is soaked with physiological saline, and subjected to shaking treatment to obtain a semi-finished product F; Step 7): the semi-finished product F is washed and soaked with water for injection to obtain a finished product G, or the method further comprises the following steps: Step 8): the finished product G is taken out, packaged, and sterilized to obtain a finished product H; or the finished product G is taken out, placed in a solution containing a lyoprotectant for freeze-drying, packaged, and sterilized to obtain a finished product H.