The determination method of the span of construction crossing curved river is researched.The research results show that the span of construction crossing natural curved river is closely related with ship track width,ship drift distance induced by flow,ship drift distance induced by wind,turbulent range of construction pier etc.The more are the above factors,the larger is the span of construction crossing curved river.And the mathematical modes of ship drift distance induced by transverse flow in curved channel,turbulent range of construction pier,the minimum span of construction crossing natural curved river are put forward.