The present invention discloses a cloud storage medical big data light-weight batch audit method facing a wireless body area network. The method comprises: initialization of an audit system; generation of medical big data signature; generation of medical data audit certificate; and medical big data audit certificate verification. A medical big data file is compressed to message authentication codes, the elliptic curve signature algorithm is employed to perform digital signature of the message authentication codes of medical data, the medical big data file is subjected to light-weight stream password encryption, and finally, signature and cryptograph of the medical data are stored into a cloud server based on the wireless body area network. The cloud storage medical big data light-weight batch audit method facing a wireless body area network ensures confidentiality of cloud user medical big data, is helpful for medical cloud users to authorize a third-party auditor to perform batch audit of a medical big data file and effectively detects whether cloud medical data is tampered or not so as to avoid doctors' clinic misdiagnosis.