The invention discloses a method for improving the homogeneous degree of low-alloy high-tensile structural steel wide and thick plate continuous casting billets. In the continuous casting process, the pulling speed of a casting machine is controlled to range from 0.78m/min to 0.90 m/min, and the superheat degree of tundish molten steel ranges from 20 DEG C to 30 DEG C; and dynamic secondary cooling control and solidification tail end heavy downward pressing are adopted. According to the method, the center segregation of the low-alloy high-tensile structural steel wide and thick plate continuous casting billets is reduced by mainly and comprehensively taking technical measures such as casting machine pulling speed stabilization, tundish superheat degree lowering, secondary cooling dynamic control and solidification tail end heavy downward pressing control, and the homogeneous degree of the continuous casting billets is improved. After the method is implemented, the effect is superior to the effect of an existing light downward pressing technology, the center segregation is well improved, the overall quality is good, the homogeneous degree is high, and the requirement for using low-alloy and high-strength structural steel can be well met.