We study the nonclassicality and decoherence in photon-loss channel of generalized squeezed Fock state, which is related to the squeezed operator with three real parameters. By using the Weyl ordering invariance under similarity transformations and the technique of integration within an ordered product of operators, we obtain the compact Wigner function of the generalized squeezed Fock state (Laguree-Gaussian function). According to the integration formula of the time evolution of the Wigner function, the Wigner expresssion in photon-loss channel is analytically deduced. In particular, we discussed the nonclassicality from the negativity of the Wigner function.