Energy efficiency of optoelectronic components is critically dependent on minimizing the undesired reflections. This paper is dedicated to a new type of silicon metasurface, possessing solar full-spectrum anti-reflection and absorption due to the multiple resonances. The proposed structure gains both in optical properties and simplified structural features. Experimental study is further carried out via using a discrete metal nanoparticles layer to build the metasurface with a series of air cavities in the silicon substrate, which therefore forms the model with different resonant modes at different wavelengths. Near-unity anti-reflection and absorption (efficiency > 97%) is achieved in the full solar radiation spectrum from 280 nm to 2500 nm. Based on the combination of multi-resonant optical properties and the structural advantageous of large area and low cost under easy-design and fabrication process, such an optical metasurface can demonstrate new insight on achieving perfect solar anti-reflector and absorber, and the related optoelectronic devices.