The invention provides a palladium-supported heterogeneous catalyst based on micro-mesoporous phenolic resin and a preparation method of the catalyst. The preparation method comprises the following steps: performing polymerization on tris(4-aldehydephenyl)phosphine and a phenolic hydroxy compound to obtain micro-mesoporous phenolic resin having a large specific surface area and being rich in hydroxyl and triphenylphosphine, and then performing a coordination reaction on palladium metal and the triphenylphosphine to obtain the porous phenolic resin based palladium metal supported heterogeneouscatalyst. The catalyst provided by the invention can high efficiently catalyze a Suzuki coupling reaction of a boric acid compound and a halide under a nitrogen or air atmosphere in an aqueous medium,and has the advantages that the preparation is simple, the catalytic yield is high, the catalyst is easy to recover and is used repeatedly and the like.