The invention belongs to the technical field of mobile medical equipment, and relates to a mobile doctor online diagnosis and treatment device and its use method. The main structure of the device includes a mobile doctor online diagnosis and treatment unit, a small nursing unit, a connecting consultation room unit, a linkage emergency room unit, Joint referral room unit, personal clinic unit, self-diagnosis unit, community hospital unit, drug information display unit, 120 telephone unit, ICU unit, general specialist hospital unit and remote expert diagnosis and treatment unit; usage methods include online consultation, joint referral, Five functional steps of private service, drug information display and linked first aid; mobile Internet-based mobile phone applications allow patients and doctors to communicate conveniently and quickly through text, voice or video at any time, saving time and costs, optimizing social medical resources, and alleviating The pressure on the medical resources of high-quality hospitals has caused the doctor resources of high-quality hospitals to sink to grass-roots hospitals. The method of use is simple, and it is easy to popularize and apply.