A method of estimating information on the projection states of projection elements (P) by using an analysis model in which discharged projection elements (P) repeatedly collided with rotation blades (13) in a projection machine having rotating blades (13). The method includes the steps of determining initial conditions including information on the size and rotation of blades (13), discharging information on the projection elements(P), and information on projection elements with respect to the blades (13) the step of storing the initial conditions, a computing step of computing the position of each projection element (P), and its velocity and direction after collision with a blade(13) based on the initial conditions, and the step of estimating information on projection state based on computation results.