Objective To study incidence of femoral neck shortening after femoral neck fracture cannulated screw fixation and its effects on patients' prognosis. Methods Seventy-eight patients with transcervical fracture treated in department of orthopedics of our hospital from May 2014 to May 2015 were selected, they were randomly divided into study group and control group, 39 cases in each group, study group underwent cannulated screw fixation, control group underwent artificial femoral head replacement, basic operation conditions in the two groups were compared, all patients were followed up in a year, incidence of femoral neck shortening, fracture healing rate in the two groups in 1 year after surgery were understood, prognosis including Harris scores, occurrence of complications in the two groups were compared. Results Compared with those the control group, operation time (62.47±11.18)min, activity time by getting out of bed (14.16±1.72)d, length of stay (16.78±2.41)d in study group were significantly shorter, intraoperative blood loss (87.40±14.60) mL was significantly less (P<0.01), incidence of femoral neck shortening in 1 year in study group 29.72% was slightly lower than control group, fracture healing rate 91.89% was slightly higher than control group, but there was no significant difference in incidence of femoral neck shortening and fracture healing rate in the two groups (P>0.05); Harris scores (82.46±5.87)score in study group was significantly lower than control group (P<0.05), complication rate was slightly higher than control group, there was no significant difference in the two groups (P>0.05). Conclusion Operation time, activity time by getting out of bed, length of stay, blood loss and other basic operation conditions of femoral neck fracture cannulated screw fixation are better than artificial femoral head replacement, incidence of femoral neck shortening and fracture healing rate are satisfied, but prognosis Harris scores, complication rate are not better than artificial femoral head replacement. So advantages and disadvantages of fracture cannulated screw fixation are obvious, it can be selected according to actual circumstance of patients in clinic.