1, used in different ways: Two-knife flow refers to the use of two weapons, but only one weapon is used for attack and the other weapon is used as a backup weapon. Double knife flow refers to using two weapons to attack, one in each hand.

2. Different skill requirements: Erdaoliu should master the skill of quickly switching weapons, so as to quickly replace spare weapons when necessary; Double knife stream needs to master the skill of left and right hand coordination before it can be attacked with two weapons.

3, the effect is different: the main advantage of the second knife stream is that it can quickly replace the spare weapon when necessary, which improves the survivability; The double-knife stream can attack multiple targets, which improves the attack efficiency.