Stringent reaction condition of effective Fenton reaction (the pH range of 3-4) hinders its further application in cancer therapy. Therefore, how to improve the efficiency of Fenton reaction in tumor site has been the main obstacle of chemodynamic therapy (CDT). Herein, we report biocompatible one-dimensional (1D) ferrous phosphide nanorods (FP NRs) with ultrasound (US)- and photothermal (PT)-enhanced Fenton properties and excellent photothermal conversion efficiency (56.6%) in the NIR II window, showing remarkably synergistic therapeutic properties. Additionally, FP NRs can be used as excellent photoacoustic imaging (PAI) and magnetic resonance imaging (MRI) agents attributed to its high photothermal conversion efficiency and excellent traverse relaxivity (277.79 mM-1 s-1). And for all we know, this is the first report on exploiting metallic phosphide response to NIR II laser (1064 nm) and US to improve the CDT effect with high therapeutic effect and PA/MR imaging, which provides a new strategy for developing more effective CDT in future practical applications.