The invention relates to a method for forming a sealing layer of a resistance strain gauge. By the method, the sealing layers, with any patterns, of the resistance strain gauges can be manufactured and the qualification rate is high. The advantage of the method is more significant, especially for the products, namely the strain gauge sealing parts with special patterns. The method comprises the following steps: 1, according to strain gauge pattern and process design parameters, designing the shape of the sealing layer pattern of the strain gauge by adopting computer aided design; 2, overlaying and cutting a sealing film into a corresponding strain gauge sealing layer pattern by mechanical engraving or laser cutting which is numerically controlled according to the design result, or manufacturing a corresponding stamping die according to the design result, and overlaying and cutting the sealing layer into a corresponding pattern sealing layer by the stamping die; and 3, sequentially aligning, adhering, laminating and curing the pattern sealing layer and the resistance strain gauge to finish formation of the sealing layer of the resistance strain gauge.