The invention discloses a manufacturing method of a simulation tree mould. The method comprises the following steps: manufacturing a mould clamping fixture, and making a simulation tree by mixed resin; manufacturing an upper mould, namely, laying oil sludge on the ground, leveling the laid oil sludge, enabling half of the simulation tree to be embedded into the oil sludge, defining a frame made of the oil sludge around the simulation tree to form a pouring tank, coating the simulation tree with a layer of vaseline, coating the vaseline layer with a silica gel layer, covering the silica gel layer by an abrasive cloth layer, pouring silica gel into the pouring tank to form a second silica gel layer, manufacturing a box body, removing the oil sludge around the simulation tree, framing the simulation tree by the box body, injecting filler into the box body, forming a filling layer on the second silica gel layer, and standing still until the layer is cured; manufacturing a lower mould, wherein the method of manufacturing the lower mould is the same as that of manufacturing the upper mould. With the method, the manufacturing cost of the simulation tree mould is very low, and thus the method is suitable for popularization.