The conditions for obtaining bail pending trial are as follows: ① The suspect is suffering from a serious illness, or a woman who is pregnant and nursing a baby; (two) after the arrest, the legal detention period is exceeded, and the case cannot be closed in time; (The legal detention period is: the investigation period is 2 months, which can be extended by 1 month with the approval of the procuratorate, and can be extended by another 2 months and ***5 months with the approval of the provincial procuratorate. The procuratorate examines and prosecutes 1 month and a half. The procuratorate may return to the public security bureau for supplementary investigation 1 month, and then review and prosecute 1.5 months, and may return for supplementary investigation twice, ***5 months. The trial period of the first instance is 1.5 months, and the trial period of the second instance is 1.5 months, ***3 months) ③ If the suspected crime is minor, it may be sentenced to public surveillance, criminal detention or fine, and it is not necessary to be sentenced to fixed-term imprisonment; (4) may be sentenced to more than fixed-term imprisonment, and bail pending trial will not cause social danger. The circumstances that cannot be released on bail pending trial are as follows: ① If the circumstances of the crime are serious, it may be sentenced to more than three years' imprisonment; (2) Escaping after committing a crime; (3) Not pleading guilty and disagreeing with the charges; (4) There are co-defendants who have not been arrested; (5) Non-local hukou, which has no fixed residence in this city, cannot be guaranteed to be available at any time. To sum up, whether the crime of assaulting a police officer can be released on bail pending trial mainly depends on the review stage, the behavior plot and whether it meets the conditions of release on bail pending trial.