The present invention provides a method for producing B4C/Al neutron-absorbing material sheet by continuous cast rolling including the steps of: 1) providing B4C particles and aluminum matrix melt, adding the B4C particles into the aluminum matrix melt while stirring the composite of the B4C particles and the aluminum matrix melt; 2) applying an electromagnetic field to the B4C particle-containing aluminum matrix melt passing through a headbox; 3) applying an ultrasonic vibration to the B4C particle-containing aluminum matrix melt passing through a casting nozzle; and 4) conducing twin roll continuous cast rolling on the B4C particle-containing aluminum matrix melt from the casting nozzle to obtain B4C/Al neutron-absorbing material sheet. The method of the present invention uses twin roll continuous cast rolling under coupled ultrasonic and electromagnetic oscillation to rapidly cool and refine the grains of the solidified composite material and realize uniform distribution of B4C particles in the aluminum matrix.