The flip-chip method has been widely used in high-density integrated circuit package due to its fast signal processing speed, high package density and high reliability. 10Sn90Pb is usually adopt as solder joint in high reliable flip-chip devices, which has the advantage of higher shear strength and higher reliability, however, its high melting point, narrow reflow process window and other characteristics bring a certain degree of difficulties to the package. In addition, the reliability of the solder in high temperature storage environment needs to be further improved. Ni is used to modify 10Sn90Pb bump, the mechanical property of Sn-Pb-Ni bump and growth rhythm of intermetallic compound (IMC) in high temperature storage is analyzed, thus, the influence of Ni to 10Sn90Pb bump reliability is assessed. The main results are as follows: Addition of proper amount of Ni can refine the IMC grains at the interface of 10Sn90Pb solder joint and reduce the growth rate of IMC under high temperature storage condition, but it also, to a certain extent, reduces the shear strength of bump, 0.05%—0.1% Ni will significantly improve performance of the bumps.