Effect of plasma spraying parameter on the strain of plasma sprayed YSZ coatings is investigated by changing the spraying power and spraying distance. The porosity is measured through using image processing method. The strain of coatings is calculated and characterized through using the digital image correlation (DIC) software system. It can be found that the porosity of YSZ coatings increases with the increment of spraying distance and the decrement of spraying power. The strain on the far field of the cracking tip shows a fluctuation tendency when the tensile forces increase. The slope of strain-force is related with the coating porosity. DIC method can be used to characterize the coating deformation in 2-dimension.