Embodiments of the invention disclose a bar code scanning device and a 
blood cell analyzer thereof. The bar code scanning device comprises: a main support, a bar code 
scanner, a slide 
carriage, a cylinder, a pressure head support 
assembly, a pressure head and an elastic element, wherein the main support is used to connect the bar code scanning device to a host; the bar code 
scanner is fixedly connected to the main support or the host; the slide 
carriage is fixedly connected on the main support; the cylinder is fixedly connected to the slide 
carriage or the main support and the cylinder comprises a cylinder 
piston rod which is extended out of the cylinder body; the pressure head support 
assembly is connected with the cylinder 
piston rod and forms cooperation connection with the slide carriage through a 
kinematic pair, and a motor is arranged on the pressure head support 
assembly; the pressure head can be rotatablely connected with the pressure head support assembly and the motor can drive the pressure head to rotate; one end of the elastic element is connected with the pressure head support assembly and the other end is connected with the slide carriage or the main support. In the invention, the elastic element provides a resilience force for the pressure head support assembly and the resilience force can buffer 
impact of the pressure head to a 
test tube. When the power is off or gas is off, the scanning device can automatically restore to an original state so that the 
test tube or a 
test tube rack can be conveniently to be taken out.