Method for preparing ZSM-5 zeolite

A method for preparing ZSM-5-based zeolite, the method comprising:

• heating a mixture including a silica source, an alumina source, a neutralizing agent, and a crystalline ZSM-5 nucleus to prepare a first solution in a solution state;
• mixing a second solution including a salt with the first solution to prepare a reaction mother liquor;
• and
• continuously supplying the reaction mother liquor to a hydrothermal synthesis reactor to perform continuous crystallization,
• wherein the following Equation 1 is satisfied:
• 0.2≤Wa/Wb≤0.40 [Equation 1]
• wherein Wa is a content of the salt in the reaction mother liquor, and Wb is a content of silica in the reaction mother liquor, and
• wherein the reaction mother liquor has a viscosity of 1000 to 2700 cP.