Further improvement on the adsorption performance of microporous organic polymers (MOPs) by delicate design remains a challenge. Herein, a magnetic hydroxyl-functioned microporous organic polymer (Fe3O4/Hy-MOP) was prepared and characterized by a series of techniques, including transmission electron microscopy, vibration sample magnetometry, Fourier transform infrared spectrometry, thermal gravimetric analysis, and zeta potential analysis. As an adsorbent for ultrasound-assisted magnetic solid phase extraction of three personal care products (PCPs, triclosan, triclocarban, and 2-hydroxy-4-methoxybenzophenone), the obtained Fe3O4/Hy-MOP exhibited excellent performance in extracting three PCPs (89–95%) from water samples owing to its hydrophilicity, inherent microporous structure, and easy magnetic separation. Moreover, probing of adsorption behavior by triclosan upon Fe3O4/Hy-MOP surfaces demonstrated that the adsorption process followed the models of Freundlich isotherm, together with pseudo-second-order kinetics. The extraction and adsorption mechanism involved polar force, π–π interaction, and hydrophobic interaction between Fe3O4/Hy-MOP and PCPs. Particularly, the stability and magnetism of Fe3O4/Hy-MOP confer excellent cycling performance, allowing for five recycling iterations without a significant decrease in performance. Such results indicated that magnetic adsorbent Fe3O4/Hy-MOP has potential for application in the extraction and removal of PCPs from actual water samples.