In order to reduce crosstalk and improve bend resistant performance, a few mode fiber with a depressed core and trench assisted cladding is proposed. The few mode fiber can support 7 LP modes within the wave length range of 1.36~1.56 m. The introduction of trench in the cladding makes the bending loss less than 1x10-7dB/mata bending radius of 1 cm, the effective refractive index difference between each modes is higher than 10-3.Based on the finite element method, the influences of structural parameters such as depressed core, trench on the effective refractive index, mode field area, and bending performance are analyzed. Numerical analysis results show that the introduction of trench is beneficial for reducing bending losses of higher-order modes.