The invention discloses a spray head installation frame of a bus fire extinguishing system. The spray head installation frame comprises a left transverse plate and a right transverse plate located on the right portion. A left hanging frame is fixedly arranged on the left transverse plate and provided with a left fixing thread hole. A right hanging frame is fixedly arranged on the right transverse plate and provided with a right fixing thread hole. Two parallel guide rails are horizontally arranged between the left transverse plate and the right transverse plate. A lead screw is horizontally installed on the right transverse plate through a bearing. A sliding table is installed on the lead screw in a threaded connection mode. The sliding table can slide in a left-right friction mode relative to the guide rails. The sliding table is provided with a spray head installation thread hole. The right transverse plate is provided with a motor. An output shaft of the motor is fixedly connected with the right end of the lead screw. The spray head installation frame has the advantages of being convenient to use, good in fire extinguishing effect and the like.