A liquid injection device includes a driving circuit supplying, to an actuator, a driving signal including a prior driving pulse and a subsequent driving pulse supplied after the prior driving pulse. Where a speed of a leading tip of a prior liquid pillar injected from the nozzle by the prior driving pulse is V3, a speed of a leading tip of a subsequent liquid pillar injected from the nozzle by the subsequent driving pulse is V4, a time period from start of the injection of the prior liquid pillar until start of the injection of the subsequent liquid pillar is t4a, a difference between a time period from the injection of the prior liquid pillar from the nozzle until division of the prior liquid pillar in the case where the prior driving pulse is supplied to the actuator but the subsequent driving pulse is not supplied to the actuator, and the time period t4a, is t4b, and a time period from start of the injection of the prior liquid pillar until separation of the prior liquid pillar from the nozzle in the case where the prior driving pulse is supplied to the actuator but the subsequent driving pulse is not supplied to the actuator is t3a, t4a≤t3a and V4≥V3×(t4a/t4b+1) are satisfied.