A three-dimensional scene model generating method, comprising: S1: a pre-processing stage comprising: S11: analyzing and extracting a plurality of object structure groups of a scene from a scene model library, wherein each object structure group defines the semantic relationship of objects in the scene; S12: calculating a Gaussian distribution function of the relative position of the objects in each object structure group; S2: a generating stage comprising: S21: inputting a scene expressed by a sketch, and retrieving candidate models for each object in the sketch in the model library; S22: determining an object model corresponding to the sketch based on the retrieval result in S21 and the semantic relationship in S1; S23: calculating the initial position for each of the corresponding object model according to the sketch; S24: finding out a local optimal position according to the initial position calculated in S23 and the Gaussian distribution function in S12 using a gradient descent method, and placing each object model of S22 according to the local optimal position to obtain a final scene model, wherein the local optimal position is the placement position of the model. S1: a pre-processing stage comprising: S11: analyzing and extracting a plurality of object structure groups of a scene from a scene model library, wherein each object structure group defines the semantic relationship of objects in the scene; S12: calculating a Gaussian distribution function of the relative position of the objects in each object structure group; S11: analyzing and extracting a plurality of object structure groups of a scene from a scene model library, wherein each object structure group defines the semantic relationship of objects in the scene; S12: calculating a Gaussian distribution function of the relative position of the objects in each object structure group; S2: a generating stage comprising: S21: inputting a scene expressed by a sketch, and retrieving candidate models for each object in the sketch in the model library; S22: determining an object model corresponding to the sketch based on the retrieval result in S21 and the semantic relationship in S1; S23: calculating the initial position for each of the corresponding object model according to the sketch; S24: finding out a local optimal position according to the initial position calculated in S23 and the Gaussian distribution function in S12 using a gradient descent method, and placing each object model of S22 according to the local optimal position to obtain a final scene model, wherein the local optimal position is the placement position of the model. S21: inputting a scene expressed by a sketch, and retrieving candidate models for each object in the sketch in the model library; S22: determining an object model corresponding to the sketch based on the retrieval result in S21 and the semantic relationship in S1; S23: calculating the initial position for each of the corresponding object model according to the sketch; S24: finding out a local optimal position according to the initial position calculated in S23 and the Gaussian distribution function in S12 using a gradient descent method, and placing each object model of S22 according to the local optimal position to obtain a final scene model, wherein the local optimal position is the placement position of the model.