The invention relates to a complete production unit for long glass fiber reinforced polypropylene materials, which comprises a long glass fiber pre-heating device, a long glass fiber surface treating device, an immersion device, and a bunching and coating device. The long glass fiber pre-heating device is connected with the long glass fiber surface treating device in a transition manner; the long glass fiber surface treating device is connected with the immersion device in a transition manner; the immersion device is connected with the bunching and coating device in a transition manner; the long glass fiber surface treating device comprises a variable diameter pressing roll and a liquid coupling agent atomizer; the immersion device has a box-type structure; an extruder connector, a melting stock allocator, a front guide roll, a middle guide roll, a back guide roll, a pair of pressing rolls are arranged in the immersion device; a double screw extruder and the melting stock allocator form a melting stock conveying passage through the extruder connector; the front guide roll, the middle guide roll, the pair of pressing rolls and the back guide roll are connected sequentially in a transition manner; and a cooling device, a pulling device and a grain-sized dicing device are sequentially distributed at the outlet end of the bunching and coating device. Therefore, a production line is formed. The process is widely used for producing long glass fiber reinforced polypropylene materials.