I will present a new method of renormalizing singular stochastic PDEs based on the Wilsonian renormalization group theory and the Polchinski flow equation. The method is applicable to a large class of semi-linear parabolic SPDEs with a fractional Laplacian, an additive noise and a polynomial non-linearity. In particular, in the case of the four-dimensional torus and the cubic non-linearity it covers the whole sub-critical regime. A nice feature of the developed technique is that it avoids the algebraic and combinatorial problems arising in different approaches. The talk is based on arXiv:2109.11380.