A randomized, controlled, multicenter clinical study on the effect of acupuncture-drug combination therapy based on the theory of

INTERVENTION: test group:Give the standard treatment and nursing care for severe pneumonia patients with invasive mechanical ventilation, and decoction and acupuncture based on the theory of "reinforcing earth to generate metal".;control group:Give the standard treatment and nursing care for severe pneumonia patients with invasive mechanical ventilation ,and the same amount of decoction based on the theory of "reinforcing earth to generate metal" that has been diluted 20 times and acupuncture with non‐meridians and non‐acupoints.; CONDITION: Severe pneumonia PRIMARY OUTCOME: mechanical ventilation time;30‐day weaning success rate; SECONDARY OUTCOME: TCM Syndrome Score;Diaphragm function; INCLUSION CRITERIA: ?Age over 18 years old ?The duration of invasive mechanical ventilation is greater than 96h ?Meet the above diagnostic criteria for pneumonia, severe pneumonia, and difficult‐to‐wean ?Meet the diagnostic criteria for dual deficiency of the lung‐spleen pattern in traditional Chinese medicine ? Obtain the consent of the subjects or their family members.