A molecular sieve (i) or (ii), characterized in that the molecular sieve (i) being SCM-1 molecular sieve has an empirical chemical composition as illustrated by the formula "a first oxide · a second oxide", wherein the ratio by molar of the first oxide to the second oxide is 20-2000, preferably 25-200, the first oxide is silica, the second oxide is alumina, and the molecular sieve has an X ray diffraction pattern as substantially illustrated in the following table, 2θ (°) d-spacing (Å) relative intensity (I / I 0 × 100) 4.22±0.30 21.04±1.48 w-s 7.17±0.18 12.32±0.31 vs 7.99±0.20 11.07±0.28 m-s 9.71±0.13 9.10±0.12 m-s 14.37±0.14 6.16±0.06 m-s 22.67±0.29 3.92±0.05 w-m 26.03±0.23 3.42±0.03 s and that the molecular sieve (ii) being SCM-2 molecular sieve has an empirical chemical composition as illustrated by the formula "a first oxide · a second oxide · an organic template · water", wherein the ratio by molar of the first oxide to the second oxide is 20-2000, preferably 25-200, the ratio by weight of the organic template to the first oxide is 0.03-0.38, preferably 0.07-0.27, the ratio by weight of water to the first oxide is 0-0.15, preferably 0.02-0.11, the first oxide is silica, the second oxide is alumina, and the molecular sieve has an X ray diffraction pattern as substantially illustrated in the following table, wherein the organic template is the combination of a first organic template and a second organic template, the first organic template is one or more selected from the group consisting of hexamethyleneimine having a C/N ratio of 6, piperidine having a C/N ratio of 5, 2-methyl piperidine having a C/N ratio of 5 and homopiperazine having a C/N ratio of 2.5, and the second organic template is N,N-diethyl cyclohexylamine having a C/N ratio of 10, dicyclohexylamine having a C/N ratio of 12 and N-methyl dicyclohexylamine having a C/N ratio of 13 and quinoline having a C/N ratio of 9, 2θ (°) d-spacing (Å) relative intensity (I / I 0 × 100) 6.38±0.14 13.84±0.30 w 7.15±0.13 12.36±0.22 vs 7.94±0.12 11.13±0.17 m 9.54±0.13 9.27±0.13 w-m 21.98±0.17 4.04±0.03 m 25.96±0.15 3.43±0.02 m-s 26.43±0.16 3.37±0.02 m the molecular sieve (i) being SCM-1 molecular sieve has an empirical chemical composition as illustrated by the formula "a first oxide · a second oxide", wherein the ratio by molar of the first oxide to the second oxide is 20-2000, preferably 25-200, the first oxide is silica, the second oxide is alumina, and the molecular sieve has an X ray diffraction pattern as substantially illustrated in the following table, 2θ (°) d-spacing (Å) relative intensity (I / I 0 × 100) 4.22±0.30 21.04±1.48 w-s 7.17±0.18 12.32±0.31 vs 7.99±0.20 11.07±0.28 m-s 9.71±0.13 9.10±0.12 m-s 14.37±0.14 6.16±0.06 m-s 22.67±0.29 3.92±0.05 w-m 26.03±0.23 3.42±0.03 s and that the molecular sieve (ii) being SCM-2 molecular sieve has an empirical chemical composition as illustrated by the formula "a first oxide · a second oxide · an organic template · water", wherein the ratio by molar of the first oxide to the second oxide is 20-2000, preferably 25-200, the ratio by weight of the organic template to the first oxide is 0.03-0.38, preferably 0.07-0.27, the ratio by weight of water to the first oxide is 0-0.15, preferably 0.02-0.11, the first oxide is silica, the second oxide is alumina, and the molecular sieve has an X ray diffraction pattern as substantially illustrated in the following table, wherein the organic template is the combination of a first organic template and a second organic template, the first organic template is one or more selected from the group consisting of hexamethyleneimine having a C/N ratio of 6, piperidine having a C/N ratio of 5, 2-methyl piperidine having a C/N ratio of 5 and homopiperazine having a C/N ratio of 2.5, and the second organic template is N,N-diethyl cyclohexylamine having a C/N ratio of 10, dicyclohexylamine having a C/N ratio of 12 and N-methyl dicyclohexylamine having a C/N ratio of 13 and quinoline having a C/N ratio of 9, 2θ (°) d-spacing (Å) relative intensity (I / I 0 × 100) 6.38±0.14 13.84±0.30 w 7.15±0.13 12.36±0.22 vs 7.94±0.12 11.13±0.17 m 9.54±0.13 9.27±0.13 w-m 21.98±0.17 4.04±0.03 m 25.96±0.15 3.43±0.02 m-s 26.43±0.16 3.37±0.02 m