A control method of a gas turbine which is provided with a multi can type combustor consisting of a plurality of unit combustors, each of which has a first stage combustion section for diffusion combustion and a second stage combustion section for premix combustion. Combustion states in the first and second stage combustion sections are monitored to take in quantities representative of the combustion conditions as control factors. The combustion in the second stage combustion section is assumed to be abnormal when the taken in quantities exceed an allowable limit and the combustion in the first and second stage combustion sections is changed to independent combustion only in the first stage combustion section when the number of unit combustors, each of which is assumed to be abnormal, exceeds a predetermined number of the unit combustors.