The invention relates to a grid-connected type micro-grid economic operating method based on sequence operation. Sequence operation is conducted on multiple random variables such as draught fan output, photovoltaic power generation and loads in a grid-connected type micro-grid to generate an equivalent load probabilistic sequence, the probability of meeting the demands of equivalent load power is calculated, and thus the probability of meeting reliability constrains is calculated. The random variables such as draught fan output, photovoltaic power generation and the loads in the grid-connected type micro-grid are taken into consideration, and the actual operating state is better met; compared with a traditional random simulating method, the calculating efficiency is obviously improved through the application of the sequence operation theory; the defect that the calculation results of all times are different in the random simulating method is overcome; the met constrain conditions are expressed in a probability mode, and higher visibility is achieved.