Capturing volatile radioactive nuclides including iodine (I129 or I131 ) is one of the major problems to be solved for environmental sustainability. Multiple types of functional microporous materials such as metal organic frameworks and covalent organic frameworks have been constructed for iodine emission control. However, most of the microporous materials are limited by their weak binding force with iodine and low stability, leading to low capture efficiencies. Herein, the synthesis of pyridyl conjugated microporous polymer networks with large surface areas (PCMP-Y) up to 1304 m2 g-1 and high yields up to 95% via a simple Yamamoto cross-coupling reaction, is reported. The PCMP-Y carries amine and pyridine N groups which have stronger interactions with iodine molecules. The high specific surface areas and porosities of PCMP-Y facilitate iodine capture, delivering a maximum adsorption capacity of 4.75g g-1 in a short time (3 h), which is superior to a majority of porous materials reported. Moreover, the reversible desorption nature of PCMP-Y capturing iodine imparts a platform for metal-free heterogeneous catalyst, which can be applied to synthesize aminobenzothiazole medicines via O2 -promoted cascade reactions.