Biological causes:

Experts believe a number of biological factors may contribute to quick ejaculation, including:
Abnormal reflex activity of the ejaculatory system
Weak PC Muscles (pubbocoxygennus muscle)

Psychological causes:

Some doctors believe that early sexual experiences may establish a pattern that can be difficult to change later in life such as:
The Techniques which you use during love making,
Inability to apply or use any ejaculatory delay method,

Risk factors :

Various factors can increase your risk of quick ejaculation, including:
Stress: Emotional or mental strain in any area of your life can play a role in quick ejaculation, often limiting your ability to relax and focus during sexual encounters.

Certain medications: Rarely, drugs that influence the action of chemical messengers in the brain (psychotropic) may cause quick ejaculation.