Abstract: The shear strength of the soldering position was taken as the characterization parameter,and the thrust measured by push-pull meter was converted into the shear strength of the chip solder joint. Parameters of reflow soldering in the flip chip LED package were optimized. The experimental results showed that when the design of reflux furnace temperature was unreasonable,the proportion of shear strength below 30 MPa was 17%,the proportion of 30 ～ 35 MPa was 11%,the proportion of 35 ～ 40 MPa was 11%,the proportion of 40 ～ 45 MPa was 15%,and the proportion of more than 45 MPa was only 46%. While using the optimized temperature,there was no shear strength below 35 MPa,the proportion of 35 ～ 40 MPa was 5%,the proportion of 40 ～ 45 MPa was 6%,and the proportion of more than 45 MPa was 89%. It was observed that settings of different soldering temperatures had a great impact on soldering shear strength of flip chip packaging. Through optimization of reflow soldering parameters,the size and number of cavities in the soldering surface could be effectively reduced.