Pressing type writing instrument

A pressing type writing instrument, wherein it comprises:

• a pen holder,
• a refill provided with a pen tip, which is disposed inside the pen holder;
• a pressing and positioning assembly comprising a guide member, a sliding member and a positioning member, wherein a guide chute provided with a rotating driving part and a positioning matching part thereon is formed on the guide member;
• the sliding member is mounted on the guide member and is capable of sliding along a direction of a length of the guide chute, the positioning member is rotatably mounted on the sliding member;
• a positioning portion is formed on the positioning member, which is slidably disposed within the guide chute;
• the guide member is disposed within the pen holder and sliding member is connected to the refill;
• and
• a spring disposed within the pen holder and used to reset the refill or the sliding member;
• and
• a pen cap provided on the sliding member;
• in which, during the process of the sliding member causing the positioning member to move toward the rotating driving part, the rotating driving part is used to be in contact with the positioning portion to allow the positioning member to rotate and the positioning matching part is used to cooperate with the positioning portion to limit the pen tip of the refill to protrude to the outside of the pen holder.