In this talk, I will discuss about my soon-to-appear work on the searches for the light dark matter with quadratic interactions with SM fields only. This will lead to the effective interactions between the light dark matter and the nucleon fields phi^2 N N/f below the QCD confinement scale, which can be thought as potential barrier for the dark matter wind in the presence of ordinary matter. When the potential barrier is large enough compared with the momentum of the dark matter, the dark matter flux will bounce back from the ordinary object, as a result inducing a pressure force on the object. After taking into the constraints from Supernova cooling, BBN and gravitational inverse square law test, there exists parameter spaces in our model which can be searched for by utilizing this force effect on the experiment for the space test of the weak equivalence principle.