A compact multimode interference (MMI) splitter with silicon photonic nanowires on silicon-on-insulator (SOI) substrate is designed and fabricated. The footprint of the MMI section is only approximately 3×10 (\mu m). The simulation results show that the device may have a low excess loss of 0.04 dB. The transmission loss of the silicon photonics wire is measured to be 0.73±0.3 dB/mm. The compact size and low transmission loss allow the device to be used in ultra-compact photonic integrated circuits. The device exhibits a good light splitting function. In a spectral range of 1549–1560 nm, the excess loss is 1.5 dB and the average imbalance between the two channels is 0.51 dB.