The invention relates to a tomato root-knot nematode disease and tobacco mosaic virus disease resistant gene marker and a method. The method provides two pairs of high-efficiency primers InMi1-F/InMi1-R and InMi2-F/InMi2-R of a tomato root-knot nematode disease resistant gene (Mi-1.2), and three pairs of high-efficiency primers InSW1-F/InSW1-R, InSW2-F/InSW2-R and InSW3-F/InSW3-R of tomato tobacco mosaic virus disease resistant gene (SW-5b), and the method can be used for more accurately judging the resistance of the plant. According to the primers and method for the tomato disease-resistant gene related marker, a PCR product can be detected through polyacrylamide gel electrophoresis, the amplification band type is clear, multiple primers can be repeated, and the accuracy is higher.