The whole line conveying system includes: internal and external wire line roller table, cylinder head line roller table, piston connecting rod line roller table. The internal and external assembly line adopts the international leading bevel gear transmission technology to ensure a long service life and maintenance-free. The piston connecting rod line adopts the upper and lower double connecting rod line, which fully takes into account the optimization of the customer's workshop space. The AGV adopts an automatic scheduling system to connect the pulling of materials between the interior, exterior and cylinder head lines.