In this paper, we study nonuniform average sampling problem in multiply generated shift-invariant subspaces of mixed Lebesgue spaces. We discuss two types of average sampled values: average sampled values {< f, psi(a)(. - x(j), .- y(k))>:j, k is an element of J} generated by single averaging function and average sampled values {< f, psi(xj,yk)>:j, k is an element of J} generated by multiple averaging functions. Two fast reconstruction algorithms for these two types of average sampled values are provided.