The invention relates to the field of biotechnology and gene engineering, and in particular to low-temperature esterase from metagenomes, a low-temperature esterase encoding gene and an application of the low-temperature esterase. The low-temperature esterase is Est18, a nucleotide sequence of the low-temperature esterase is as shown in SEQ ID NO: 1, and an amino acid sequence of encoding of the low-temperature esterase is as shown in SEQ ID NO: 2. The Est18 is a low-temperature alkaline esterase and relatively stable at the temperature of 40 DEG C or less, the optimum temperature of the Est18 is 20 DEG C, the optimum pH (potential of hydrogen) of the Est18 is 8.0, and the maximum activity of the Est18 is larger than 80% when the pH is 11.0.