Abstract: A defect detection method includes: obtaining an image of a first defective block output by the SPI machine; wherein the first defective block is a solder paste block that is not qualified for printing after being detected by the SPI machine; processing the image of the first defective block; detecting whether solder paste printing in the first defective block is qualified; and determining that the first defective block is a second defective block and determining a defect type of the first defective block when the solder paste printing of the first defective block is not qualified. A terminal device and a non-volatile storage medium therein, for performing the above-described method, are also disclosed.