We find the free field construction of basic $W$-current and screening currents for deformed $W$-superalgebra ${\cal W}_{q,t}\bigl(A(M,N)\bigr)$ associated with Lie superalgebra type $A(M,N)$. Using this construction, we introduce higher $W$-currents obtain a closed set quadratic relations among them. These are independent choice Dynkin-diagrams $A(M,N)$, though not. This allows us to define by...