  In this paper we study the perturbation theory of $\Phi^4_2$ model on the
whole plane via stochastic quantization. We use integration by parts formula
(i.e. Dyson-Schwinger equations) to generate the perturbative expansion for the
$k$-point correlation functions, and prove bounds on the remainder of the
truncated expansion using PDE estimates; this in particular proves that the
expansion is asymptotic. Furthermore, we derive short distance behaviors of the
$2$-point function and the connected $4$-point function, also via suitable
Dyson-Schwinger equations combined with PDE arguments.
