Abstract: In order to reduce carbon emissions of an intersection without right turn control during a free passage of right turn vehicles, this paper proposes a time optimization scheme considering an intersection where vehicles turn right under a low carbon target.A carbon emission model is constructed where vehicles turning left or going straight pass through the intersection, the data are collected when pedestrians dissipate through the intersection, and the real pedestrian dissipation time is simulated by the random method.At the same time, a carbon emission model under the condition of a lack of right turning control is proposed by using the gap traffic theory. In order to solve this problem, an improved multi-strategy sparrow search algorithm is proposed. Compared with particle swarms and the sparrow search algorithm, carbon emissions per hour of this model are respectively 16.649 4kg and 8.359 4 kg lower during peak hours, and are also 6.805 5 kg lower than those of Webster algorithms.Compared with particle swarms and the sparrow search algorithm, carbon emissions per hour of this model are respectively 9.430 1 kg and 0.916 9 kg lower during normal hours, and are also 5.481 kg lower than those of Webster algorithms.