The utility model discloses a visual alertness detector, comprising a plurality of PDA hand-held terminals which are provided with data storage modules and are configured to provide a visual alertnesstest platform for a user; the analysis device is configured to analyze the data provided by the alertness test platform; the wireless communication module is configured to transmit the data generatedby the test platform to the analysis device; and the box body is sequentially provided with three shock absorption layers from top to bottom, and the three shock absorption layers are used for placing the visual alertness detector main body and all accessories. According to the visual alertness detector, online and offline visual alertness evaluation of multiple persons and response speed calibration of the PDA handheld terminal and the computer terminal can be achieved, system errors are effectively eliminated, the box body is compact in structural design and good in anti-seismic and anti-collision effect, and all components of the visual alertness detector can be well protected.