The invention discloses a method applied to evaluation of flow conductivity of shale-gas-combined sand fracturing fracture. The method comprises the following steps: a, simulating a sand bar transporting process in shale-gas-slickwater-combined sand fracturing fracture by means of an experiment device for simulating flowing of proppants in a visual fracture net to obtain sand bar transporting video of the combined sand fracturing fracture under different experiment conditions; b, obtaining a distribution curve of the proppants with different particle diameters by virtue of a gray processing method and a point-by-point scanning method and obtaining distribution shape function of the proppants with different particle diameters by virtue of a linear regression method; c, building the sand bar distribution shape function of an API flow guide chamber by utilizing geometric similarity principle according to the size of the API flow guide chamber, paving shapes of the corresponding proppants and implementing evaluation of flow conductivity of shale-gas-combined sand fracturing fracture. The method is capable of simply and accurately implementing quantitative evaluation of the flow conductivity of shale-gas-combined sand fracturing fracture; experiment support is provided for optimizing the combined sand fracturing design and improving the flow conductivity of the shale fracturing fracture.