A method for detecting clogging of a subsurface flow constructed wetland, including the steps of firstly emptying water in the subsurface flow constructed wetland, and then measuring the apparent resistivity of the subsurface flow constructed wetland bed after the water is emptied, wherein the water holding capacity of clogging sediments in the clogged region after emptying is strong, the apparent resistivity of this region is further measured to be lower than an unclogged region and the clogged region can thus be positioned and analyzed, the apparent resistivity of the region clogged more seriously is lower and the degree of clogging can thus be quantitatively analyzed.