Abstract: The present invention relates to a Layer 2 adapter selecting system, including a Layer 3 packet requirements extracting module, a destination Layer 2 address acquiring module, a Layer 2 adapter metric acquiring module, an appropriate Layer 2 adapter identifier selecting module, a packet caching module and a packet scheduling module; wherein the packet caching module is configured to cache a received Layer 3 packet; the Layer 3 packet requirements extracting module is configured to read the Layer 3 packet and extract the type and a parameter value of the requirements; the Layer 2 adapter metric acquiring module is configured to acquire instant metric parameter values of each of the adapters; the appropriate Layer 2 adapter identifier selecting module calculates an adapter identifier and a Layer 3 packet metric; the destination Layer 2 address acquiring module is configured to acquire a Layer 2 address of each of the adapters associated with a destination Layer 3 address; and the packet scheduling module calls