The present invention discloses an instrument guiding method of a surgical navigation system, which includes: obtaining a 3D vector of a preplanned instrument path determining the plane perpendicular to the 3D vector of the preplanned instrument path and passing through the end of the preplanned instrument path displaying the end of the preplanned instrument path as a target marker on a display reading a dynamic 3D vector of the instrument orientation projecting the dynamic 3D vector to the plane so as to generate a projection vector displaying two end points of the projection vector as two dynamic markers on the display and guiding the instrument to make the centers of the dynamic markers overlap with the center of the target marker to generate an overlapped image. The present invention provides visualization of the instrument orientation and the preplanned instrument path to help doctors improve the efficiency of operation.本發明係為一種手術導引系統之器械導引方法,其包括下列步驟:取得醫師規劃之一預定器械路徑3D向量;藉由處理單元取得與預定器械路徑3D向量垂直且通過其終點之一預定切平面;將預定器械路徑3D向量之終點作為一目標標記顯示於一顯示器上;讀取器械之一動態3D向量;將動態3D向量投影至預定切平面而產生一投影向量;將投影向量之兩標記點作為兩動態標記顯示於顯示器上;以及導引器械使動態標記之中心重疊於目標標記之中心以產生一重疊影像。本發明能讓醫師於手術導引時可以視覺化的方式了解器械與預定器械路徑之間的關係,以加速手術的進行。S100‧‧‧手術導引系統之器械導引方法S10‧‧‧取得一預定器械路徑3D向量S20‧‧‧取得一預定切平面S30‧‧‧顯示一目標標記於一顯示器上S40‧‧‧讀取一動態3D向量S50‧‧‧產生一投影向量S60‧‧‧顯示二動態標記於顯示器上S65‧‧‧結合醫學影像S70‧‧‧導引器械以產生一重疊影像
