  In this paper, we aim to study the asymptotic behaviour for a class of
McKean-Vlasov stochastic partial differential equations with slow and fast
time-scales. Using the variational approach and classical Khasminskii time
discretization, we show that the slow component strongly converges to the
solution of the associated averaged equation. In particular, the corresponding
convergence rates are also obtained. The main results can be applied to
demonstrate the averaging principle for various McKean-Vlasov nonlinear SPDEs
such as stochastic porous media type equation, stochastic $p$-Laplace type
equation and also some McKean-Vlasov stochastic differential equations.
