The invention discloses a combustor and a gas water heater with the same. The combustor comprises at least one combustion unit. Each combustion unit comprises a combustor shell and a rectifying device, wherein the combustor shell is provided with a first dense combustion flame opening, a second dense combustion flame opening and a light combustion opening; the rectifying device is arranged in thecorresponding light combustion opening; a first blind channel and a second blind channel are limited between the two side walls of the light combustion opening and the rectifying device; the first blind channel is located between the first dense combustion flame opening and a plurality of light combustion flame openings; the second blind channel is located between the second dense combustion flameopening and the multiple light combustion flame opening; the height difference between the top face of the outer side wall of the first blind channel and the top face of the rectifying device as wellas between the top face of the outer side wall of the second blind channel and the top face of the rectifying device is H1, the height difference between the top face of the outer side wall of the first dense combustion flame opening and the top face of the rectifying device as well as between the top face of the outer side wall of the second dense combustion flame opening and the top face of therectifying device is H2, and H2 is greater than or equal to H1. According to the combustor, the emission of nitric oxide in smoke is reduced.