A new type of optical isolator with double core fiber is proposed. The optical isolator has been fabricated with two fiber tips and a lens pair. The lens pair has a confocal plane in between with same optical axis direction and optical cross function. Integrated with two fiber tips, the function of optical isolator is duplicated in comparison with conventional optical isolator with single fiber tip. This isolator couples optical radiation in one direction from two fibers to the corresponding double output fibers. The innovative isolator with dual core fiber collimator is assembled and tested at 1550nm wavelength. Experimental results show that the forward insertion loss from two channels reaches 0.43dB and 0.31dB, loss from backward isolation reaches 43dB and 40dB respectively. The cross talk of both channels achieves 60dB. It's the most important that the isolator, which features duplicated function and good performances, also has a low cost and a small dimension comparatively