The invention belongs to the technical field of molecular sieve preparation, and relates to an SSZ-13 molecular sieve, a method for regulating and controlling the crystal morphology of the SSZ-13 molecular sieve and application of the SSZ-13 molecular In order to solve the technical problems that the SSZ-13 molecular sieve is large in particle size and uneven in particle size distribution due to the fact that the SSZ-13 molecular sieve morphology control technology is difficult to control in the prior art, the method for controlling the SSZ-13 molecular sieve crystal morphology is provided, a silicon source, an aluminum source, alkali and a structure-directing agent are added into pure water to be mixed evenly, then a crystal morphology control agent is added for further treatment, and the SSZ-13 molecular sieve crystal morphology is obtained. According to the method, the crystal morphology and size of the SSZ-13 molecular sieve can be effectively controlled, the SSZ-13 molecular sieve of a cubic, polyhedral or spherical crystal can be prepared, the grain size of the crystal is small and can be adjusted within a certain range, and the grain size distribution is uniform. When being used as an SCR (selective catalytic reduction) denitration catalyst to be applied to the field of automobile exhaust treatment, the catalyst shows high denitration catalytic performance, high hydrothermal aging stability and wider effective working temperature range.