By comparing the water simulation of the breathable bricks， under the same pressure， and it is presented as intermittent outgassing， and the bubbles are large in volume but small in quantity .The diffuse breathable brick has little disturbance to the ladle， and the air outlet is a dense air outlet， and the number of small bubbles is large；And the flow value of slit type breathable brick is greater than that of diffusion type， and the disturbance of the molten steel in the ladle is greater. By comparing the production test of breathable brick， it is found that the average residual length of the diffusion breathable brick used in the same ladle is significantly higher than that of the slit breathable brick. The desulfurization rate of dispersion type breathable bricks 75.94% is lower than that of slit type breathable bricks 85.19%. By comprehensive comparing the test data of Aspex， flaw detection and macrostructure of GCr 15 varieties produced under the same process route， the results show that when using the diffusion breathable tile and slit breathable tile， the average number of inclusions is 218.2， number of oxide inclusions that size≤5 μm 7.8，Aspex inclusion index 5.6， qualified rate of automatic flaw detection 99.67%， defect-free rate of water immersion ultrasonic C-scan inspection 96.67%，average grade of B thin 0.534. In summary ， it is the best solution.