This article reports a distributed feedback (DFB) laser-pumped cesium atomic experimental magnetometer, showing how the sensitivity is influenced by the following 5 kinds of parameters: laser light intensity, laser frequency, radiofrequency intensity, temperature of cesium absorption cell, and the pressure of the buffer gas in the cell. Results of the experiments show that each of the five parameters has some influence on the sensitivity of the magnetometer, especially the laser frequency, radiofrequency intensity, and temperature of cesium absorption cell, which can even improve the sensitivity by 10 times. Recently we have obtained a sensitivity of 2.5 pT/Hz1/2.