A method for optimal configuration of distributed executing mechanisms and sensors of flexible spacecraft comprises the following steps that a series of candidate nodes for installing executing mechanisms (such as miniature control moment tops) and sensors (such as spin rate meters) are selected on the flexible spacecraft; it is assumed that the executing mechanisms and the sensors are installed on the candidate nodes, controllability indexes and observability indexes are calculated according to controllability and observability matrixes of a system, and judgment indexes of combined characteristics of the executing mechanisms and the sensors are calculated based on controllability and observability subspaces; configuration nodes are selected according to index values. By the adoption of the scheme, the effects of the executing mechanisms and the sensors in the system can be played to the most degree, the configuration quantity is minimized, and a system structure is simplified. The method is good in universality and simple in structure, belongs to innovative approaches for domestic and oversea relevant research and application, has a great market competitiveness, fills the blank of practicable schemes and theoretical research in the relevant fields and has very strong engineering practicability and theoretical guiding significance.