The invention discloses a 
pickling line tandem cold mill withdrawal and straightening 
machine control method. When the yielding strength of a target steel grade is smaller than or equal to 300 MPa, the 
ductility of a withdrawal and straightening 
machine is 2.3%-2.5%, and the engagement amount is 30 mm to 35 mm; when 300 MPa<the yielding strength<=450 MPa, the 
ductility is 1.8%-2.2%, and the engagement amount is 35 mm to 40 mm; when the yielding strength is larger than 450MPa, the 
ductility is set 0.5%-1.2%, and the engagement amount is 40 mm to 42 mm; and meanwhile according to the difference of the thickness or the width of front 
strip steel and rear 
strip steel, weld joint excessive withdrawal and straightening 
machine modes are divided into four kinds. By means of the 
pickling line tandem cold mill withdrawal and straightening 
machine control method, the withdrawal and straightening machine achieves automatic grouping control over steel grades in different yielding strength levels, normal withdrawal and straightening of the withdrawal and straightening machine can be guaranteed, the loads of the withdrawal and straightening machine can also be effectively reduced, normal 
pickling of the 
strip steel is guaranteed, and the withdrawal and straightening up-to-standard rate reaches 98% or above; and selection of the weld joint excessive withdrawal and straightening machine 
modes guarantees normal pickling of weld joint heads and tails, and the strip breakage accident caused by poor weld joint quality is avoided.