The invention discloses a method for preparing an edible mushroom culture bar, which comprises the following steps: (1) crushing and uniformly stirring substrate raw materials; (2) heating, pressurizing and sterilizing the raw materials and reducing the pressure of the raw materials to a normal pressure with stirring; (3) performing surface heat exchange and reducing a temperature; (4) adding sterilized substrate components which cannot withstand high temperature and high pressure, adjusting water content and uniformly stirring the mixture; (5) inoculating liquid strains with stirring; and (6) bagging the strains to obtain the edible mushroom culture bar. As the surface heat exchange method is adopted to reduce the temperature, the method, compared with the prior art, has the advantages that: cooling water does not need sterilizing and can be recycled; heat generated by the surface heat exchange can be recycled, which saves the heat and shortens cooling time; labor required for bag-by-bag injection addition with an injector is saved; and sterilizing time is short, and labor intensity and cost are low.