The invention provides a testing method of high speed downlink packet access utmost thuoughput. The method includes steps as follows: confirming present priority queuing waitting for scheduling from priority queuing of subdistrict through scheduling algorithm; high speed downlink packet access dispatcher in base station selects transmission block size used by current scheduling according with channel quality indicator reported by user equipment, present subdistrict code number and high speed downlink packet access usable power; selected transmission block is packaged according with MAC-hs PDU; bit amount per second sent by user equipment or subdistrict is counted, the counted speed is upmost thuoughput of the base station for supporting the user equipment or subdistrict. The testing method of high speed downlink packet access utmost thuoughput provided by the invention can test upmost thuoughput of high speed downlink packet access operation of the base station simply and accurately under the condition of no influence by RNC and CN completely.