Novel method for manual viscosity control

The invention relates to a novel method for manual viscosity control. The novel method for the manual viscosity control is used for guiding melt viscosity control when production conditions are changed. The novel method for the manual viscosity control concretely comprises the following concrete control steps that abnormal production conditions are found; melt pressure in a pipeline is measured through a spinning pipeline pressure measurement system; the pressure difference of a filter and the rotational speed of a boost pump before 40 minutes are deduced; melt viscosity drop is calculated in a conversion mode through a pressure conversion formula I and a modification formula II of an actual viscosity change; the melt viscosity drop which is calculated in the conversion mode is used as production instructions to adjust the vacuum degree and other process conditions; manual control over melt viscosity is achieved. The novel method for the manual viscosity control has the advantages that the melt viscosity cont