Background: Low-background gamma-ray spectrometer is used widely.Low-background laboratory with good shielding performance can reduce the indoor background values effectively

and reduce the impact of the background on low background gamma spectrometer measurements

but currently there were few literatures on the low background laboratory design.Purpose: This paper attempts to propose a design for a low background laboratory with good shielding performance

and effectively improve the sensitivity of instrument.Methods: We analyzed the various factors（cosmic ray

radon and its progeny

the earth’s natural gamma radiation

and building material） affecting the indoor background

and carried out calculation and analysis on different factor.Results: It is found that radon and radon progeny had almost no effect

and cosmic rays and building materials were the main influence factors.Conclusions: In view of the different influence factors on the background

we can design a low-background laboratory which meets the requirements by taking different shielding measures.