Grass trimmer and cord delivering method of grass trimmer

A grass trimmer, comprising:

• an extending rod extending longitudinally,
• an housing arranged at one end of said extending rod,
• a handle arranged on said extending rod and spaced from said housing by a distance,
• a grass trimming head connected to said housing,
• a main motor driving the grass trimming head to rotate around an axis, and
• a main switch controlling said main motor;
• said grass trimming head comprises:
• a base,
• a cap matched and connected to said base, and
• a spool arranged between said base and said cap;
• said spool has a first state static relative to said base and said grass trimmer further comprises a cord delivering mechanism that comprises a cord delivering electronic switch independent of said main switch and a control device, said cord delivering electronic switch operably electrically controls said control device to enable said spool to be in a second state capable of generating a rotary speed difference relative to said base.