The invention provides an LGA welding process method in printed circuit board processing. The method comprises the steps that a fixing jig used for LGA printing and a small leakage plate are produced; baking and dehumidifying are carried out on LGA; the fixing jig used for LGA printing and the small leakage plate are used to print solder paste on the LGA; a reflow oven is used to carry out reflowing on the solder paste on the LGA; a full-automatic printing press is used to print the solder paste on a printed circuit board; a chip mounter is used to carry out surface mounting on the LGA; reflowing soldering is carried out on the LGA; and X-RAY detection is carried out. According to the invention, the requirement of once first pass yield of batch production can be met; product quality problems of insufficient solder leaks, large holes, continuous solder and the like are reduced; rework is reduced; the cost is saved; the use of the LGA reaches a new and high field; and the LGA welding process method has a high market value and a large application prospect.