The invention discloses a method for assessing wireless data service carrying efficiency. The method is characterized by collecting user original data on interfaces between core network network elements; screening out cells, of which data service multiplexing degree is lower than a first data service multiplexing degree threshold, from wireless network statistics to serve as idle cells of the data service; analyzing collected user original data and determining content transmission average delay of each cell in the idle cells; and determining wireless data service carrying efficiency of each cell in non-idle cells according to the content transmission average delay of each cell in the idle cells. The invention also discloses a device for assessing the wireless data service carrying efficiency. With the scheme in the invention, the actual use perception of the user can be accurately assessed, the assessment of the wireless data service carrying efficiency of each cell in the non-idle cells is realized, and the influence of the core network side, inter-operator interface load and website servers on the wireless data service carrying efficiency is fully taken into consideration.