Benefiting from laser preheat and magnetization, magnetized liner lnertial fusion (MagLIF) has a promising potential because theoretically it can dramatically lower the difficulties in realizing the controlled fusion. In this paper, the end loss effect caused by laser preheat in MagLIF process is chosen as an objective to explore its influences, and a one-dimensional and heuristic model of this effect is proposed based on the jet model of ideal fluid, in which the high-dimensional influences, such as geometric parameters and sausage instability, are taken into consideration. To complete the verification progress, the calculation results of one-dimensional MIST code and two-dimensional programs TriAngels and HDYRA are compared, and the application scopes of this heuristic model are discussed and summarized. Based on this model, the key parameters and influences of the end loss effect on the MagLIF implosion process and pre-heating effect are obtained. The calculation results show that the MagLIF load maintains a similar hydrodynamic evolution process in most of the implosion processes with different laser entrance radii, and experiences the same percentage of mass (～16%) lost during stagnation stage. With the same driving current, the fuel temperature will rise higher in the model with more mass losing, so the fusion yields do not change too much. The mass loss ratio seems to play a dominant role. It is recommended to design the laser entrance hole as small as possible in the experiment to increase the yield. The predictions obtained after considering the end loss effect lower the preheating temperature and fusion yield, but no change happens to the regularity trend. As the liner height increases, the preheating temperature, peak current, fuel internal energy, and fusion yield each still show a monotonically downward trend. Therefore, under the premise of fixed driving capability and laser output capability, it is suggested that the liner height in MagLIF load design should be as short as possible. The established heuristic model and conclusions are helpful in better understanding the physical mechanism in the process of MagLIF preheat and end loss.