A double cladding seven-core photonic crystal fiber (PCF) is reported with zero dispersion wavelength (ZDW) at 1036 nm and the nonlinear coefficient of 2.43 W-1·km-1 at 1060 nm. A gain-switched all polarization-maintaining fiber laser system with central wavelength of 1060 nm, pulse width of 160 ps, repetition rate of 1 MHz, beam quality M2<1.3 and average power of 4.5 W is utilized to pump a 35 m-long seven-core PCF, allowing the supercontinuum generation (SCG) with output power of 2.443 W covering wavelength from 500 nm to 1700 nm. The far field of seven-core PCF is measured, the pattern of which is in agreement with the calculated far field of in-phase supermode. The experiment can be a useful reference for the high power supercontinuum source.