Tire contact state estimation method

The present invention comprises: means for obtaining on the rotational speed of the tire, braking-driving force, and yaw angle information of the lateral force generated acquisition step; information about the drive speed acquisition step of acquiring information about the system and the force used by information, calculating a first correlation between the speed and the strength of the braking-driving force, and by obtaining step obtains the information about the yaw angle and the lateral force generated on the information of the calculated slip angle with the a second correlation strength intensity correlation between the lateral force calculating step; means for detecting a first correlation strength in the correlation strength calculation step with respect to a first predetermined reference value is increased or reduced by more than a first threshold value, and detecting a second correlation strength in the correlation strength calculation step is increased or reduced with more than a second threshold value variation detection step for a second predetermined reference value; and a road surface based on a detection result of the change detecting step, estimating the tire contact the step of estimating at least two sTATUS wear, internal pressure condition of the tire and of the tire.