S1. starting a hole-processing apparatus having a tool configured to drill a hole on a workpiece;

S2. causing the tool to rotate using a tool driving device and forward feeding the tool with predetermined processing parameters;

S3. while forward feeding the tool, monitoring the rotation speed of the tool driving device by using a sensor; when the rotation speed of the driving device changes, performing step S4; and when the rotation speed of the driving device does not change, performing step S2;

S4. determining a material of the workpiece based on the rotation speed of the driving device, and automatically adjusting the processing parameters to adapt to the material of the workpiece;

S5. continuing forward feeding the tool to process the hole;

S6. continuing monitoring the rotation speed of the driving device, when the rotation speed of the driving device changes, performing step S7; and when the rotation speed of the driving device does not change, performing step S5;

S7. determining whether the hole-processing process has been completed based on the rotation speed of the driving device, when the hole-processing process has been completed, performing step S8; and when the hole-processing process has not been completed, performing step S4; and

S8. retracting the tool,

wherein in step S4, determining the material of the workpiece based on the rotation speed comprises the steps of:

S41. determining a no-load rotation speed of the driving device n₀ when the tool rotates without contacting the workpiece;

S42. applying a variable torque on an output end of the driving device, causing the driving device to rotate, adjusting the applied torque while measuring the rotation speed n of the tool driving device corresponding to the variable torque, establishing by curve-fitting a mathematical function T_d=ƒ(n), wherein an output torque of the tool driving device T_d correlates with the rotation speed of the driving device n;

S43. establishing a torque prediction model of T_d=g(n,m,k), wherein m is a coefficient related to the workpiece material, and k is an array of parameters selected from a tool diameter, an eccentricity, a feed speed, a revolution speed;

S44. combining the function T_d=ƒ(n) obtained in step S42 and the function T_d=g(n,m,k) obtained in step S43 to obtain an equation ƒ(n)=g(n,m,k);

S45. determining initial coefficients m_i that correspond to all materials in the to-be-processed workpiece, i being a positive integer, and initial coefficient k_a corresponding to m₁; and

S46. substituting k=k_a and m=m₁ into the equation ƒ(n)=g(n,m,k) in step S44 to obtain the rotation speed of the driving device n_i and inputting n_i into the controller.