In this paper, we study the dynamics of a non-autonomous semilinear degenerate parabolic equation ut − div(σ(x)∇u) + f (u) = g(x, t) defined on a bounded domain Ω ⊂ R N with smooth boundary. We first establish a Nash-Moser-Alikakos type a priori estimate for the difference of solutions near the initial time; Then we prove that the solution process U (t, τ) is continuous from L 2 (Ω) to D 1 0 (Ω, σ) w.r.t. initial data; And finally show that the known (L 2 (Ω), L 2 (Ω)) pullback D λ-attractor indeed can attract in D 1 0 (Ω, σ)-norm. Any differentiability on the forcing term is not required.