The invention relates to a machining load control system based on instruction sequence optimization, which has a structure as follows: a parameter setting module is used for setting machining parameters, a machining constraint condition, a CAD (computer-aided design) data of machining parts and machining codes, providing a geometrical model of the parts and a machining instruction sequence code data, and generating a corresponding parameter file; a learning module is used for learning the cutting load, vibration and machining precision corresponding to the machining instruction sequence of the parts, generating a data file containing the parameter setting information and learning result of the learning module, and providing the cutting load, vibration and machining precision to an analysis module; the analysis module is used for confirming a to-be-optimized position and the machining instruction sequence code and graphically displaying the to-be-optimized position and the machining instruction sequence code; and an optimizing module is used for optimizing the machining instruction sequence, generating the machining instruction sequence code, performing statistic analysis, and generating an optimized machining instruction sequence code file. By using the machining load control system based on instruction sequence optimization, the high-precision machining is realized under the existing condition.