We propose a facile and scalable in situ polymerization strategy to selectively introduce the active quinone-based components across the carbon nanotube (CNT) surface. It can be observed that the optimized poly(anthraquinonyl sulfide) (PAQS)/CNT composites exhibit excellent activity and selectivity with a H2O2 yield ratio of approximately 91% at 0.5 V (vs. RHE), together with satisfactory stability at 0.5 V over 20 h. The electrocatalytic performance is correlated with the synergistic effect between PAQS and CNTs. That is, PAQS grafted with abundant quinone groups facilitates the 2 e- ORR process to produce H2O2, and the conductive CNT scaffold is beneficial for the uniform distribution of PAQS and ensures the fast electron transport through the composites.