The present disclosure provides a motor stator, a motor and a bus. The motor stator includes a stator tooth. The stator tooth includes a tooth root and a tooth crest. The tooth crest is provided on the tooth root. The tooth crest includes a first tooth crest part and a second tooth crest part. The first tooth crest part and the second tooth crest part are provided on two sides of the tooth root along the circumference of the motor stator, respectively, and a tooth crest air gap is formed between the first tooth crest part and the second tooth crest part. According to the present disclosure, the motor stator is adapt to reduce magnetic flux leakage, and enhance the utilization rate of a permanent magnet and output torque.