MoB/CoCr, a novel material for thermal spraying, with high durability in molten alloys is used to resist erosion by molten Al-Si alloy in solar thermal power generation. The microstructure and phase component of coatings were characterized, and the coatings were also studied on bond strength and thermal shock resistance. The durability of the MoB/CoCr coatings prepared by low pressure plasma spraying (LPPS) has been investigated using a molten-metal immersion tester. The results showed that phase component of powder and coating had little change. The coatings have dense structure and excellent combination with substrate. The main constituents of coatings remain invariant and the coatings have excellent properties of bond strength and thermal shock resistance. The immersion tests revealed that the MoB/CoCr coating has much higher durability without dissolution in the molten Al-12.07wt.%Si alloy.