A kit for detecting NRAS gene mutation, comprising: internal reference detection reagent, which includes the internal reference gene specific primers, internal reference gene specific probes and dNTP solution, in which the said internal reference gene specific primers are SEQ ID No: 1 and SEQ ID No: 2, and the said internal reference gene specific probe is SEQ ID No: 16; NRAS mutation detection reagent, which includes the NRAS mutant gene specific primers, NRAS mutant gene specific probes, internal control gene specific primers, internal control gene specific probes and dNTP solution, in which the said NRAS mutant gene is selected from: NM1, i.e. NRAS gene Codon 12 34G>A; NM2, i.e. NRAS gene Codon 12 35G>A; NM3, i.e. NRAS gene Codon 13 38G>A; NM4, i.e. NRAS gene Codon 61 181C>A; NM5, i.e. NRAS gene Codon 61 182A>T; NM6, i.e. NRAS gene Codon 61 182A>G; and NM7, i.e. NRAS gene Codon 61 183A>T; for NM1 mutation, the said specific primers are SEQ ID No: 5 and SEQ ID No: 8; for NM2 mutation, the said specific primers are SEQ ID No: 6 and SEQ ID No: 8; for NM3 mutation, the said specific primers are SEQ ID No: 7 and SEQ ID No: 8; for NM4 mutation, the said specific primers are SEQ ID No: 9 and SEQ ID No: 13; for NM5 mutation, the said specific primers are SEQ ID No: 10 and SEQ ID No: 13; for NM6 mutation, the said specific primers are SEQ ID No: 11 and SEQ ID No: 13; for NM7 mutation, the said specific primers are SEQ ID No: 12 and SEQ ID No: 13; the said NRAS mutant gene specific probes are selected from SEQ ID No: 14 or SEQ ID No: 15; the said internal control gene specific primers are SEQ ID No: 3 and SEQ ID No: 4; the said internal control gene specific probe is SEQ ID No: 17; Taq DNA polymerase; and NRAS positive quality control, which includes the internal reference gene, NRAS mutant gene and internal control gene fragments, in which the said internal reference gene sequence is SEQ ID No: 18; the said internal control gene fragment sequence is SEQ ID No: 19; the sequence of said NRAS gene is SEQ ID No: 20 or SEQ ID No: 21. internal reference detection reagent, which includes the internal reference gene specific primers, internal reference gene specific probes and dNTP solution, in which the said internal reference gene specific primers are SEQ ID No: 1 and SEQ ID No: 2, and the said internal reference gene specific probe is SEQ ID No: 16; NRAS mutation detection reagent, which includes the NRAS mutant gene specific primers, NRAS mutant gene specific probes, internal control gene specific primers, internal control gene specific probes and dNTP solution, in which the said NRAS mutant gene is selected from: NM1, i.e. NRAS gene Codon 12 34G>A; NM2, i.e. NRAS gene Codon 12 35G>A; NM3, i.e. NRAS gene Codon 13 38G>A; NM4, i.e. NRAS gene Codon 61 181C>A; NM5, i.e. NRAS gene Codon 61 182A>T; NM6, i.e. NRAS gene Codon 61 182A>G; and NM7, i.e. NRAS gene Codon 61 183A>T; for NM1 mutation, the said specific primers are SEQ ID No: 5 and SEQ ID No: 8; for NM2 mutation, the said specific primers are SEQ ID No: 6 and SEQ ID No: 8; for NM3 mutation, the said specific primers are SEQ ID No: 7 and SEQ ID No: 8; for NM4 mutation, the said specific primers are SEQ ID No: 9 and SEQ ID No: 13; for NM5 mutation, the said specific primers are SEQ ID No: 10 and SEQ ID No: 13; for NM6 mutation, the said specific primers are SEQ ID No: 11 and SEQ ID No: 13; for NM7 mutation, the said specific primers are SEQ ID No: 12 and SEQ ID No: 13; the said NRAS mutant gene specific probes are selected from SEQ ID No: 14 or SEQ ID No: 15; the said internal control gene specific primers are SEQ ID No: 3 and SEQ ID No: 4; the said internal control gene specific probe is SEQ ID No: 17; NM1, i.e. NRAS gene Codon 12 34G>A; NM2, i.e. NRAS gene Codon 12 35G>A; NM3, i.e. NRAS gene Codon 13 38G>A; NM4, i.e. NRAS gene Codon 61 181C>A; NM5, i.e. NRAS gene Codon 61 182A>T; NM6, i.e. NRAS gene Codon 61 182A>G; and NM7, i.e. NRAS gene Codon 61 183A>T; for NM1 mutation, the said specific primers are SEQ ID No: 5 and SEQ ID No: 8; for NM2 mutation, the said specific primers are SEQ ID No: 6 and SEQ ID No: 8; for NM3 mutation, the said specific primers are SEQ ID No: 7 and SEQ ID No: 8; for NM4 mutation, the said specific primers are SEQ ID No: 9 and SEQ ID No: 13; for NM5 mutation, the said specific primers are SEQ ID No: 10 and SEQ ID No: 13; for NM6 mutation, the said specific primers are SEQ ID No: 11 and SEQ ID No: 13; for NM7 mutation, the said specific primers are SEQ ID No: 12 and SEQ ID No: 13; the said NRAS mutant gene specific probes are selected from SEQ ID No: 14 or SEQ ID No: 15; the said internal control gene specific primers are SEQ ID No: 3 and SEQ ID No: 4; the said internal control gene specific probe is SEQ ID No: 17; Taq DNA polymerase; and NRAS positive quality control, which includes the internal reference gene, NRAS mutant gene and internal control gene fragments, in which the said internal reference gene sequence is SEQ ID No: 18; the said internal control gene fragment sequence is SEQ ID No: 19; the sequence of said NRAS gene is SEQ ID No: 20 or SEQ ID No: 21.