We report here a direct knitting Method for preparation of highly robust, effective while air- and moisture-tolerant, and readily recyclable three-dimensional (3D) porous polymer-Pd network (PPPd) from the widely used Pd(PPh3)4. Electro-beam induced Pd atom crystallization was observed for the first time in organic polymer and revealed the ultrafine dispersion of palladium atoms. Challenging types of Suzuki-Miyaura couplings, reductive coupling of aryl halides and oxidative coupling of arylboronic acid were successively catalyzed by PPPd in aqueous media. Also catalytically selective CH functionalization reactions were achieved with orders of magnitude more efficient than conventional Pd homogeneous catalysts. The strategy developed here provides a practical method for easy-to-make yet highly efficient heterogeneous catalysis.